SIRT1对氧化应激下人小梁网细胞功能的影响

目的:通过在人小梁网细胞(human trabecular meshwork cell,HTMC)中过表达沉默信息调节因子2相关酶1(silent information regulator 1,SIRT1),探讨SIRT1对氧化应激下HTMC功能的影响.方法:将SIRT1过表达慢病毒和GFP阴性对照慢病毒按照最佳(m...     

SIRT1、PGC-1α在原发性开角型青光眼患者小梁网组织中的表达及意义

目的　检测原发性开角型青光眼（primary open-angle glaucoma，POAG）患者小梁网组织中沉默信息调节因子2相关酶1（silent information regulator factor 2 related enzyme 1，SIRT1）和过氧化物酶体增殖物激活受体γ辅激活因子1α（peroxisome proliferator-activated receptor γ coactivator-1α，PGC-1α）表达水平，探讨其与POAG小梁网组织功能损伤的关系。方法　收集2017年1月至2018年4月在海南医学院第一附属医院手术切除确诊为POAG 40例（40眼）患者的小梁网组织为POAG组样本，另取30例眼球供体的小梁网组织为对照组样本，采用RT-PCR法检测2组小梁网组织中SIRT1、PGC-1α mRNA表达，免疫组织化学染色法检测SIRT1、PGC-1α蛋白表达，同时检测过氧化物酶（peroxidase dismutase，POD）和超氧化物歧化酶（superoxide dismutase，SOD）水平。结果　POAG组小梁网组织中SIRT1、PGC-1α mRNA表达水平（0.11±0.03、0.32±0.10）均低于对照组（0.24±0.07、0.67±0.21）（均为P＜0.05）；POAG组小梁组织中SIRT1表达与PGC-1α表达呈正相关关系（r=0.759，P＜0.05）；POAG组小梁网组织中POD水平［（102.59±22.37）×10³ U·L^-1］高于对照组［（73.46±15.81）×10³U·L^-1］（P＜0.05），SOD水平［（347.62±50.73）U·L^-1］低于对照组［（412.57±61.25）U·L^-1］（P＜0.05）；POAG组小梁网组织中SIRT1、PGC-1α表达与POD水平均呈负相关关系（r=-0.636、-0.737，均为P＜0.05），与SOD水平均呈正相关关系（r=0.662、0.614，均为P＜0.05）。结论　POAG患者小梁网组织中SIRT1和PGC-1α表达水平降低，可能在线粒体功能失调和氧化应激对小梁网的损伤中发挥重要调控作用。     

牵拉力对人小梁网细胞活性及房水流出调节功能影响的实验研究

 目的 观察强机械牵拉力作用下，人小梁网细胞活性及房水流出调节相关基因表达的改变。设计 实验研究。 研究对象 人小梁网细胞。方法 依据牵拉力作用时间将原代培养的小梁网细胞分为0 h对照、12 h、24 h三组。采用FLEXCELL力学加载设备对体外培养的人小梁网细胞施加最大延伸比例为22%的机械牵拉力。用流式细胞学的方法检测各组小梁细胞的凋亡比率，采用蛋白印迹法检测细胞存活相关蛋白的表达，用定量聚合酶链式反应（qPCR）检测与房水流出调节相关的15个基因在牵张力作用下的表达量，并比较实验组与对照组间的差异。主要指标 小梁网细胞凋亡率、整合素-Fak信号通路相关分子、房水流出调节相关的15个基因的表达量。结果 在牵拉力作用后，对照组、12 h组、24 h组的凋亡率分别为0.71%±0.18%、0.77%±0.19%、0.87%±0.31%（P=0.7298）；三组磷酸化Akt蛋白的相对表达量分别为1.00、2.17±0.06、1.69±0.07（P<0.01）；整合素信号通路中的磷酸化Fak的相对表达量分别为1.00、1.85±0.09、1.31±0.08（P<0.01）。此外，参与调节房水流出的基质金属蛋白酶1、2、3、7、9、10、11、12、14基因表达均升高（P均<0.01）；基质金属蛋白酶抑制剂1、2、3基因的表达均降低（P均<0.01）；白介素6基因相对表达量分别为1.00、1.28±0.06、1.47±0.06（P<0.01）。结论 高强度的机械牵拉能够增加小梁网细胞的活性，增强房水流出调节相关因子的表达，这可能是schlemm管成形术降低眼压的机制之一。     

miR-135a/b靶向SIRT1调控葡萄膜黑色素瘤细胞的迁移

目的：研究microRNA-135a/b（miR-135a/b）对葡萄膜黑色素瘤（UM）细胞迁移能力的调控作用及其机制。方法：实验研究。采用定量RT-PCR检测UM标本和癌旁组织中miR-135a/b的表达水平。将miRNA模拟物转染入UM细胞（M23和SP6.5）过表达miR-135a/b，转染无义序列作为对照组（NC）。利用小RNA干扰技术和慢病毒过表达载体感染技术分别下调和上调细胞中SIRT1蛋白表达水平，分别以无义小干扰RNA（siNC）和插入无义序列的慢病毒载体（Lv-NC）作为阴性对照。采用划痕实验和Transwell实验检测细胞的迁移能力。双萤光素酶报告实验用于鉴定miR-135a/b的靶基因。Western blot检测SIRT1蛋白的表达水平。采用独立样本t检验进行数据分析。结果：定量RT-PCR结果显示miR-135a/b在UM组织较癌旁组织的表达水平明显下调（miR-135a：t=6.38，P=0.003；miR-135b：t=23.26，P<0.001）。划痕实验和Transwell实验结果显示，与NC组相比，miR-135a/b过表达M23和SP6.5细胞迁移距离减小（miR-135a：t=36.01、8.98，均P<0.01；miR-135b：t=27.53、10.51，均P<0.01）且迁移细胞数量减少（miR-135a：t=7.04、7.02，均P<0.01；miR-135b：t=5.01、7.32，均P<0.01）。双萤光素酶实验证实，miR-135a/b能够明显抑制SIRT1野生组萤光素酶的荧光值（miR-135a：t=2.88，P=0.028；miR-135b：t=4.99，P=0.003）；Western blot结果表明，与NC组相比，过表达miR-135a/b的M23和SP6.5细胞中SIRT1的蛋白水平下调（miR-135a：t=9.93、4.13，均P<0.01；miR-135b：t=4.66、6.20，均P<0.01）。siSIRT1转染后划痕实验和Transwell实验结果显示，与siRNC组相比，M23和SP6.5细胞中下调SIRT1蛋白水平后细胞的迁移距离减小（siSIRT1-I：t=13.88、11.78，均P<0.01；siSIRT1-II：t=31.20、6.27，均P<0.01）且迁移细胞数量减少（siSIRT1-I：t=7.57、4.66，均P<0.01；siSIRT1-II：t=5.58、3.25，均P<0.05）。M23和SP6.5细胞中上调SIRT1蛋白水平同时过表达miR-135a/b，Transwell实验结果显示，细胞的迁移数量较仅过表达miR-135a/b升高（miR-135a+Lv-SIRT1：t=4.10、2.75，均P<0.05；miR-135b+Lv-SIRT1：t=2.99、2.49，均P<0.05）。结论：miR-135a/b在UM中明显下调且通过靶向结合SIRT1 mRNA 3'非翻译区抑制UM细胞的迁移，提示miR-135a/b-SIRT1信号轴在UM发展中发挥重要作用。     

miR-181a靶向沉默信息调节因子相关酶1在过氧化氢诱导的人小梁网细胞氧化应激中的调节作用

目的　探讨miR-181a对过氧化氢（H₂O₂）诱导的人小梁网细胞（HTMCs)氧化应激的调节作用及其机制。方法　HTMCs随机分为空白组（0 μmol·L^-1 H₂O₂）、200 μmol·L^-1 H₂O₂组、400 μmol·L^-1 H₂O₂组、600 μmol·L^-1 H₂O₂组,分别使用相应浓度H₂O₂处理HTMCs,24 h后MTT法检测各组细胞存活率,实时荧光定量PCR（qRT-PCR）检测各组细胞miR-181a mRNA表达,Western blot检测各组细胞中沉默信息调节因子相关酶1（SIRT1）蛋白表达。根据转染物的不同分为miR-181a inhibitor组、miR-181a NC组、miR-181a mimics组、miR-181a inhibitor+si-SIRT1组和miR-181a inhibitor+si-NC组,使用二氯二氢荧光素-乙酰乙酸酯（DCFH-DA）荧光探针检测各组细胞内活性氧（ROS）含量,使用超氧化物歧化酶（SOD）和丙二醛（MDA）ELISA试剂盒检测各组细胞SOD和MDA活性,使用Annexin V FITC/PI联合流式细胞仪检测细胞凋亡情况,Western blot检测各组细胞中SIRT1蛋白表达,双荧光素酶报告基因实验对靶点进行验证。结果　与空白组比较,200 μmol·L^-1 H₂O₂组、400 μmol·L^-1 H₂O₂组、600 μmol·L^-1 H₂O₂组细胞存活率均降低（均为P<0.05）。细胞miR-181a mRNA的表达随着H₂O₂浓度的增加而增加,SIRT1蛋白的表达随着H₂O₂浓度的增加而降低（均为P<0.05）。与miR-181a NC组比较,miR-181a mimics组细胞凋亡率、MDA活性和ROS含量均升高,细胞SOD活性、SIRT1蛋白表达均降低,miR-181a inhibitor组细胞凋亡率、MDA活性和ROS含量均降低,细胞SOD活性、SIRT1蛋白表达均升高（均为P<0.05）。双荧光素酶报告基因实验证实,miR-181a靶向抑制SIRT1蛋白的表达。与miR-181a inhibitor+si-NC组比较,miR-181a inhibitor+si-SIRT1组细胞凋亡率、MDA活性和ROS含量均升高,SOD活性降低（均为P<0.05）。结论　miR-181a可能通过靶向SIRT1调节H₂O₂诱导的HTMCs氧化应激作用。     

白细胞介素-1α对猪小梁细胞基质金属蛋白酶／基质金属蛋白酶抑制剂表达的影响

背景房水外流通路的阻塞或小梁网细胞外基质（ECM）的异常堆积导致房水流畅系数降低是引起眼压升高的原因之一,基质金属蛋白酶（MMPs）和组织金属蛋白酶抑制剂（TIMPs）的平衡对ECM的代谢至关重要,白细胞介素-1α（IL-1α）可以通过调节MMPs的表达而调节房水的外流。目的研究猪重组IL-1α对体外培养的猪眼小梁细胞MMP-2、MMP-3及TIMP-1表达的影响。方法从猪眼取出带有小梁组织的巩膜,用组织块培养法培养小梁细胞并进行传代,第3代的猪小梁细胞应用纤维连接蛋白（FN）和层黏连蛋白（LM）进行鉴定。第3代小梁细胞血清饥饿培养24h后分为2组,对照组加入无血清培养基,IL组加入10m／L IL-1α,分别培养30min。采用细胞免疫化学法分析IL组MMP-2、MMP-3及TIMP-1蛋白在培养小梁细胞中的表达;采用逆转录聚合酶链反应（RT—PCR）法检测小梁细胞中MMP-2mRNA、MMP-3mRNA及TIMP-1 mRNA的表达,并与对照组的检测结果进行比较。结果传3代的细胞对FN和LM呈现阳性反应。与对照组比较,IL组小梁细胞中MMP-3和TIMP-1蛋白的表达量（A值）明显升高,差异均有统计学意义（t=-7．694、t=-5．199,P〈0．05）,但2组间小梁细胞中MMP-2表达的差异无统计学意义（t=-2．365,P〉0．05）。IL组小梁细胞中MMP-3mRNA和TIMP-1mRNA的表达量（A值）明显高于对照组,差异均有统计学意义（t=-3．025、t=-1．921,P〈0．05）,而2组间小梁细胞中MMP-2mRNA的表达差异无统计学意义（t=-1．173,P〉0．05）。结论外源性IL-1α能增加猪眼小梁细胞中MMP-3、TIMP-1的表达,引起MMP-3／TIMP-1平衡改变,促进小梁网ECM的分解,增加房水外流,而对MMP-2的表达无影响。     

靶向血管内皮生长因子的RNA干扰抑制氧诱导视网膜病变小鼠视网膜新生血管生成的研究

目的探讨玻璃体腔注射靶向血管内皮生长因子（VEGF）的RNA干扰慢病毒抑制氧诱导视网膜病变（OIR）小鼠视网膜新生血管生成的作用及其机制。方法实验研究。构建4对针对靶基冈小鼠VEGF的siRNA干扰载体,筛选并进行慢病毒包装。60只C57Bif6J小鼠分成4组（每组15只）：正常对照组．OIR模型组,OIR＋空载体组,OIR＋VEGF-RNA干扰组。OIR＋空载体组和OIR＋VEGF-RNA干扰慢病毒组的小鼠在生后第5天玻璃体腔注射相应的1μ1的7.5×10^7空载体慢病毒和VEGF-RNA干扰慢病毒。后3组小鼠在生后第7天建立OIR模型。第17天时FITC-Dextran灌注视网膜铺片观察4组小鼠视网膜血管形态及面积变化,视网膜铺片免疫荧光染色检测紧密连接蛋白Claudin-5和Occludin的分布变化．Westernblot检测VEGF、磷酸肌醇3激酶（P13K）、酪氨酸蛋白激酶SRC、磷酸化细胞外信号调节激酶（P-ERK）蛋白表达量的变化。数据采用单因素方差分析进行比较。结果FITC-Dextran灌注视网膜铺片显示正常组视网膜血管分布呈均匀网状;RNA干扰组新生血管面积（0．271399mm^2）明显较OIR模型组（1.212782mm^2）、空载体组（1．152504mm^2）少（F=449．924,P〈0．01）。OIR模型组和空载体组间差异无统计学意义,其余两两间差异均有统计学意义（P〈0．01）。视网膜铺片免疫荧光染色显示紧密连接蛋白Claudin-5和Occludin在RNA干扰组中与正常组相似,呈均匀光滑线性分布,而在OIR模型组、空载体组的分布中断、不均匀,在新生血管团中可见团块状的强荧光;VEGF的RNA干扰组中VEGF、P13K、酪氨酸蛋白激酶SRC和p-ERK的蛋白表达量较OIR模型和空载体组低。结论玻璃体腔注射靶向VEGF的RNA干扰慢病毒能有效抑制OIR小鼠模型中VEGF及其下游通路蛋白的表达．从而抑制视网膜新生血管的形成．为临床上早产儿视网膜病变的防治提供了新思路和新途径。     

SIRT1对葡萄膜黑色素瘤细胞增殖的表观遗传调控

目的：探讨沉默信息调节蛋白1（SIRT1）对人葡萄膜黑色素瘤细胞增殖的影响。方法：实验研究。通 过定量PCR和Western blot法检测SIRT1在葡萄膜黑色素瘤细胞（M23和SP6.5）和正常人葡萄膜黑色 素细胞（DM78、UM95和UM96）中的表达。在葡萄膜黑色素瘤细胞（M23、SP6.5）中，用EX527抑 制SIRT1活性，以溶剂DMSO作为阴性对照组；用SIRT1小干扰RNA（siSIRT1）转染细胞抑制SIRT1 表达，以无义小干扰RNA（NC）转染作为阴性对照组。细胞增殖实验（MTS）、流式细胞术、平板 克隆形成实验分别检测细胞活性、细胞周期以及细胞克隆形成能力。裸鼠眼内成瘤实验检测葡萄 膜黑色素瘤细胞眼内成瘤能力。Western blot法检测增殖相关蛋白。组间数据均采用独立样本t检验 进行比较。结果：与葡萄膜黑色素细胞相比，葡萄膜黑色素瘤细胞（M23、SP6.5）中SIRT1 mRNA （t=17.08，P<0.001；t=13.24，P<0.001）和蛋白（t=6.26，P=0.008）表达水平显著升高。MTS结果显示， EX527抑制M23和SP6.5细胞活性，并呈药物浓度依赖性；与NC转染组相比，siSIRT1转染组细胞 活性显著减弱（t=5.94，P<0.001；t=10.73，P<0.001）。与溶剂DMSO组相比，EX527处理组（t=5.10， P=0.047；t=7.57，P=0.002）和SIRT1 siRNA转染组（t=6.41，P=0.003；t=6.10，P=0.004）中处于G1期 的细胞比例均显著升高。另外，M23和SP6.5细胞EX527处理组（t=5.04，P=0.001；t=5.93，P<0.001） 和siSIRT1转染组（t=11.44，P<0.001；t=8.24，P<0.001）克隆形成数量显著降低。在裸鼠眼内成瘤实 验中，与NC组相比，siSIRT1转染组眼内瘤体大小显著变小（t=5.50，P<0.001）。Western blot结果显 示，与DMSO处理组相比，EX527处理组中P21（t=4.63，P=0.010；t=7.90，P=0.001）表达升高，E2F1 （t=12.10，P=0.003；t=5.96，P=0.004）、CYCLIND2（t=36.28，P<0.001；t=16.58，P<0.001）、p-RB（t=17.55， P<0.001；t=21.34，P<0.001）表达降低，p-AKT表达下调。与NC转染组相比，siSIRT1转染组中， P21（t=5.88，P=0.004；t=10.51，P<0.001）表达升高，E2F1（t=4.60，P=0.01；t=4.89，P=0.008）、 CYCLIND2（t=5.13，P=0.007；t=5.63，P=0.005）、p-RB（t=4.45，P=0.011；t=6.53，P=0.003）表达水 平降低，p-AKT（t=9.61，P<0.001；t=6.44，P=0.003）表达下调。结论：抑制SIRT1活性或表达可以明 显抑制葡萄膜黑色素瘤细胞的增殖，提示SIRT1可以作为治疗葡萄膜黑色素瘤的一个新靶标。     

慢病毒介导的TGFβ-R2shRNA抑制人LECs细胞TGFβ—R2的表达

目的：观察转化生长因子β-R2特异性短发夹 RNA （ shRNA ）对人晶状体上皮细胞TGFβ-R2表达的影响。 方法：根据小干扰RNA （ siRNA ）的设计原则,针对转化生长因子β-受体2基因序列特征构建特异性 shRNA （ RNAi ）载体,与TGFβ-R2过表达载体共转染293 T细胞,经Western blot筛选出有效RNAi载体后,进行扩增、纯化、滴度测定,并转染培养的人LECs , qPCR 检测TGFβ-R2 siRNA慢病毒载体对TGFβ-R2 mRNA表达的影响。 结果：经Western blot 筛选,TGFβ-R2/GV115RNAi＃1对目的基因的表达敲减效果最明显,慢病毒包装,滴度为8E＋8 TU/mL,感染人LECs细胞后,对TGFβ-R2基因有显著的敲减效果,达到78．1％（P＜0．05）。 结论：TGFβ-R2 RNAi载体构建成功,并且能抑制人晶状体上皮细胞TGFβ-R2 mRNA的表达。     

miR-17-5p对小梁网细胞外基质蛋白表达的调控作用及其机制

目的　探讨miR-17-5p对小梁网细胞外基质（ECM）蛋白表达的调控作用及其机制。方法　收集原发性开角型青光眼（POAG）患者和正常小梁网组织,利用RT-PCR和Western blot分别检测miR-17-5p和Smad3表达;将人小梁网细胞（HTMCs）分为miR-17-5p mimics和miR-17-5p NC组,分别转染载有miR-17-5p mimics组和miR-17-5p NC的载体,Western blot检测HTMCs中ECM蛋白纤连蛋白（FN）、胶原蛋白I（CoL-I）、α-平滑肌肌动蛋白（α-SMA）的表达;靶基因预测库预测miR-17-5p靶基因,荧光素酶报告载体联合Western blot鉴定靶基因。HTMCs中共转染miR-17-5p mimics和Smad3过表达载体,Western blot检测各转染组细胞中Smad3、FN、CoL-I、α-SMA的蛋白表达。结果　正常小梁网组织中miR-17-5p表达量为1.16±0.11,高于POAG小梁网组织的0.19±0.04,差异有统计学意义（t=10.641,P<0.001）;正常小梁网组织中Smad3蛋白表达量为0.31±0.06,低于POAG小梁网组织的0.86±0.07,差异有统计学意义（t=8.105,P<0.001）。miR-17-5p mimics组HTMCs中FN、CoL-I和α-SMA蛋白表达均低于miR-17-5p NC组,差异均有统计学意义（均为P<0.001）;靶基因预测库预测及荧光素酶报告载体联合Western blot鉴定证实Smad3为miR-17-5p下游靶基因;miR-17-5p+Smad3转染组HTMCs中Smad3、FN、CoL-I和α-SMA蛋白表达均高于miR-17-5p+vector转染组,差异均有统计学意义(均为P<0.001)。结论　miR-17-5p 能抑制HTMCs的ECM蛋白表达,这一过程可能是通过靶向抑制Smad3表达而实现的。     

Mitogen-activated protein kinase phosphatase-1 (MKP-1) in retinal ischemic preconditioning

We previously described the phenomenon of retinal ischemic pre-conditioning (IPC) and we have shown the role of various signaling proteins in the protective pathways, including the mitogen-activated protein kinase p38. In this study we examined the role in IPC of mitogen-activated protein kinase phosphatase-1 (MKP-1), which inactivates p38. Ischemia was produced by elevation of intraocular pressure above systolic arterial blood pressure in adult Wistar rats. Preconditioning was produced by transient retinal ischemia for 5 min, 24 h prior to ischemia. Small interfering RNA (siRNA) to MKP-1 or a control non-silencing siRNA, was injected into the vitreous 6 h prior to IPC. Recovery was assessed by electroretinography (ERG) and histology. The a-and b-waves, and oscillatory potentials (OPs), measured before and 1 week after ischemia, were then normalized relative to pre-ischemic baseline, and corrected for diurnal variation in the normal non-ischemic eye. The P2, or post-photoreceptor component of the ERG (which reflects function of the rod bipolar cells in the inner retina), was derived using the Hood-Birch model. MKP-1 was localized in specific retinal cells using immunohistochemistry; levels of mitogen-activated protein kinases were measured using Western blotting. Injection of siRNA to MKP-1 significantly attenuated the protective effect of IPC as reflected by decreased recovery of the electroretinogram a and b-waves and the P2 after ischemia. The injection of siRNA to MKP-1 reduced the number of cells in the retinal ganglion cell and outer nuclear layers after IPC and ischemia. Blockade of MKP-1 by siRNA also increased the activation of p38 at 24 h following IPC. MKP-1 siRNA did not alter the levels of phosphorylated jun N-terminal kinase (JNK) or extracellular signal-regulated kinase (ERK) after IPC. The results suggest the involvement of dual-specificity phosphatase MKP-1 in IPC and that MKP-1 is involved in IPC by regulating levels of activated MAPK p38.     

UV-induced signaling pathways associated with corneal epithelial cell apoptosis

PURPOSE: UV-C irradiation of corneal epithelial cells elicits K+ channel activation, which in turn causes them to undergo apoptosis. In the present study, the intermediary role played by mitogen-activated protein kinase (MAPK) signaling pathways in mediating this response was investigated. METHODS: Western blot and kinase assays were used to measure UV-induced activation (i.e., phosphorylation) of c-Jun NH(2)-terminal kinase (JNK)/SEK, extracellular signal-regulated kinase (ERK), and p38. Corneal epithelial apoptosis was determined by measuring caspase 3 activity. RESULTS: UV-irradiation-induced increases in cell membrane K+ channel activity resulted in activations of JNK, SEK upstream of JNK, and caspase 3 downstream of JNK. Suppression of K+ channel activity with specific K+ channel blockers significantly inhibited UV-irradiation-induced activation of JNK cascades. However, suppression of K+ channel activity did not prevent hyperosmotic-stress-induced JNK activation. In addition, UV-irradiation-induced SEK/JNK activation was unaffected by removal of extracellular free Ca2+ with EGTA. CONCLUSIONS: UV-irradiation-induced corneal epithelial cell apoptosis is mediated through activation of the SEK/JNK signaling pathway. Such activation is dependent on increases in K+ channel activity, which play an important role in the early events that result in activation of this pathway.     

A distinct integrin-mediated phagocytic pathway for extracellular matrix remodeling by RPE cells.

PURPOSE: To characterize the phagocytosis of extracellular matrix components by retinal pigment epithelial cells and to determine which receptors and signal transduction pathways are involved. METHODS: Fluorescent latex beads were coated with fibronectin (FN), collagen type I or IV, or thrombospondin and incubated with human retinal pigment epithelial cells for 3 hours. Phagocytosis was quantified by flow cytometry. The effects of adhesion blocking antibodies to cell surface receptors (alpha1, alpha3, alpha5, beta1, alpha5beta1, alphavbeta3, alphavbeta5 integrins and CD36) and inhibitors of specific intracellular signaling pathways (tyrosine kinase phosphatidylinositol 3-kinase [PI3-kinase], protein kinase C [PKC], and mitogen-activated protein kinase) were determined using FN-coated beads. RESULTS: Phagocytosis of FN-coated beads was greater than phagocytosis of beads coated with collagen type I, collagen type IV, or thrombospondin or uncoated controls (P < 0.0005). Anti-alpha5, -beta1, and -alpha5beta1 antibodies markedly inhibited FN phagocytosis (P < 0.0005); the inhibitory effects of anti-alpha5 antibody were stronger in the initial stages (binding) than in the later stages (internalization) of phagocytosis. There was no significant effect on phagocytosis when anti-alpha1, -alpha3, -alphavbeta5, -alphavbeta3 or -CD36 antibodies were used. Fibronectin phagocytosis was decreased by inhibitors of tyrosine kinase (genistein, 100 microg/ml, P < 0.005) and PI3-kinase (wortmannin, 5 microM, P < 0.01), but these reagents did not affect the uncoated controls. The PKC inhibitor calphostin C (400 nM) nonspecifically increased the phagocytosis of FN-coated (P < 0.05) and uncoated beads (P < 0.01). CONCLUSIONS: Subconfluent retinal pigment epithelial cells preferentially phagocytose FN over other extracellular matrix components. Phagocytosis of FN utilizes the alpha5beta1 integrin, is mediated in part through tyrosine kinase and PI3-kinase signaling pathways, and is modulated by PKC. Phagocytosis of extracellular matrix by retinal pigment epithelial cells may represent a novel mechanism for remodeling of the provisional extracellular matrix during outer retinal wound healing.     

Identification of differentially expressed metastatic genes and their signatures to predict the overall survival of uveal melanoma patients by bioinformatics analysis

AIM: To identify metastatic genes and miRNAs and to investigate the metastatic mechanism of uveal melanoma (UVM). METHODS: GSE27831, GSE39717, and GSE73652 gene expression profiles were downloaded from the Gene Expression Omnibus (GEO) database, and the limma R package was used to identify differentially expressed genes (DEGs). Gene Ontology (GO) term enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed using the DAVID online tool. A comprehensive list of interacting DEGs was constructed using the Search Tool for the Retrieval of Interacting Genes (STRING) database and Cytoscape software. The Cytoscape MCODE plug-in was used to identify clustered sub-networks and modules of hub genes from the protein-protein interaction network. GEPIA online software was used for survival analysis of UVM patients (n=80) from the The Cancer Genome Atlas (TCGA) cohort. OncomiR online software was used to find that the miRNAs were associated with UVM prognosis from the TCGA cohort. TargetScan Human 7.2 software was then used to identify the miRNAs targeting the genes. RESULTS: There were 1600 up-regulated genes and 1399 down-regulated genes. The up-regulated genes were mainly involved in protein translation in the cytosol, whereas the down-regulated genes were correlated with extracellular matrix organization and cell adhesion in the extracellular space. Among the 2999 DEGs, five genes, Znf391, Mrps11, Htra3, Sulf2, and Smarcd3 were potential predictors of UVM prognosis. Otherwise, three miRNAs, hsa-miR-509-3-5p, hsa-miR-513a-5p, and hsa-miR-1269a were associated with UVM prognosis. CONCLUSION: After analyzing the metastasis-related enriched terms and signaling pathways, the up-regulated DEGs are mainly involved in protein synthesis and cell proliferation by ribosome and mitogen-activated protein kinase (MAPK) pathways. However, the down-regulated DEGs are mainly involved in processes that reduced cell-cell adhesion and promoted cell migration in the extracellular matrix through PI3K-Akt signaling pathway, focal adhesion, and extracellular matrix-receptor interactions. Bioinformatics and interaction analysis may provide new insights on the events leading up to the development and progression of UVM.     

Simple transscleral fixation of IOL technique without tying up haptics

AIM: To identify metastatic genes and miRNAs and to investigate the metastatic mechanism of uveal melanoma (UVM). METHODS: GSE27831, GSE39717 and GSE73652 gene expression profiles were downloaded from the Gene Expression Omnibus (GEO) database, and the limma R package was used to identify differentially expressed genes (DEGs). Gene Ontology (GO) term enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed using the DAVID online tool. A comprehensive list of interacting DEGs was constructed using the Search Tool for the Retrieval of Interacting Genes (STRING) database and Cytoscape software. The Cytoscape MCODE plug-in was used to identify clustered sub-networks and modules of hub genes from the protein-protein interaction network. GEPIA online software was used for survival analysis of UVM patients (n=80) from the The Cancer Genome Atlas (TCGA) cohort. OncomiR online software was used to find that the miRNAs were associated with UVM prognosis from the TCGA cohort. TargetScan Human 7.2 software was then used to identify the miRNAs targeting the genes. RESULTS: There were 1600 up-regulated genes and 1399 down-regulated genes. The up-regulated genes were mainly involved in protein translation in the cytosol, whereas the down-regulated genes were correlated with extracellular matrix organization and cell adhesion in the extracellular space. Among the 2999 DEGs, five genes, Znf391, Mrps11, Htra3, Sulf2, and Smarcd3 were potential predictors of UVM prognosis. Otherwise, three miRNAs, hsa-miR-509-3-5p, hsa-miR-513a-5p, and hsa-miR-1269a were associated with UVM prognosis. CONCLUSION: After analyzing the metastasis-related enriched terms and signaling pathways, the up-regulated DEGs are mainly involved in protein synthesis and cell proliferation by ribosom and mitogen-activated protein kinase (MAPK) pathways. However, the down-regulated DEGs are mainly involved in processes that reduced cell-cell adhesion and promoted cell migration in the extracellular matrix through PI3K-Akt signaling pathway, focal adhesion, and extracellular matrix-receptor interactions. Bioinformatics and interaction analysis may provide new insights on the events leading up to the development and progression of UVM.     

Activation of ERK1/2 MAP kinase pathway induces tight junction disruption in human corneal epithelial cells

Activation of protein kinase C (PKC) by exposure of cultured human corneal epithelial cells to phorbol 12-myristate 13-acetate (PMA) resulted in an increase in paracellular permeability as evidenced by a decrease in transepithelial electrical resistance (TER). A change in the membrane distribution of the tight junction protein ZO-1 was also observed in the PMA-treated cells. In contrast, when the cells were treated with PMA in the presence of PD98059, a specific inhibitor of mitogen-activated protein kinase (MAPK) kinase, all barrier characteristics were preserved, suggesting that PKC induces tight junction disruption through the activation of MAPK. The role of this signaling pathway in the regulation of epithelial permeability was further elucidated by the use of corneal epithelial-derived cell lines expressing constitutively activated (ca) or dominant-negative (dn) mutants of MAPK kinase-1 (MEK1). Transfectants of caMEK1, when compared to parental cells, had higher levels of phosphorylated extracellular regulated protein kinase (ERK), altered distribution of ZO-1 and occludin, and much reduced TER. On the other hand, dnMEK1 transfectants had lower but detectable levels of ERK phosphorylation, more flattened morphology, and, most importantly, significantly higher TER when compared to parental cells. Our study demonstrates that activation of PKC causes the disruption of tight junctions through activation of MAP kinase and that the MAP kinase signaling pathway plays a key role in the regulation of epithelial cell morphology and barrier function in the cornea.