共查询到16条相似文献,搜索用时 62 毫秒
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许瑶函 《中华实验眼科杂志》2021,(10):923-928
青光眼是一组以视网膜神经节细胞(RGCs)渐进性死亡及其轴突慢性退化为特征的神经退行性疾病,主要与病理性眼压升高有关。自噬,即细胞自我"消化",是一种细胞降解、回收机制。过度自噬或自噬受损均可能导致细胞功能障碍,甚至死亡。近年的研究表明,自噬与不同因素导致的青光眼小梁网细胞功能异常和RGCs凋亡及视神经退行性改变密切相... 相似文献
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孙瑞竹 《中华实验眼科杂志》2016,(4):375-379
青光跟是一组以视网膜神经节细胞(RGCs)丢失和视野缺损为特征的神经退行性疾病,其病理机制尚不完全清楚,眼压升高被认为是青光眼发生和发展最主要的危险因素.小梁网及Schlemm管是房水引流系统的主要组成部分,其结构或功能异常可引起房水流出的受阻进而引起眼压升高.越来越多的证据表明,氧化损伤可能在人小梁网细胞凋亡、功能障碍及其他退行性改变过程中发挥作用.氧化损伤是体内氧化和抗氧化失衡,从而引起脂质过氧化反应、蛋白质变性、DNA损伤等一系列组织病理损伤的过程.既往研究发现青光眼患者房水中氧化应激标志物水平升高,且氧化应激可引起小梁网细胞DNA氧化损伤、细胞内线粒体氧化损伤和炎症反应.本文就氧化应激在小梁网功能损伤中发挥的作用及可能的机制进行综述. 相似文献
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小梁网是前房水引流的重要通道,呈复杂的三维结构,主要的细胞成分是小梁网细胞,细胞之间有交错成多层的细胞外基质。小梁网结构和功能的改变是导致眼压失常甚至视神经损伤的重要原因。有研究发现,非编码RNA(ncRNA)的异常表达可导致小梁网细胞生存率、收缩性能和细胞外基质结构发生改变,房水流出受阻,眼压失控,是青光眼发生的重要机制。目前,与小梁网相关的ncRNA研究涉及多种ncRNA分子和多种类型青光眼,本文将对微小RNA、长链ncRNA和环状RNA等ncRNA在小梁网组织中的研究进展进行综述。 相似文献
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目的 研究原花青素(Procyanidins,PC)对H2O2诱导人眼小梁细胞(human trabecular meshwork cells,HTMC)氧化应激的抗氧化作用,为青光眼的临床治疗提供实验依据.方法 将正常HTMC进行细胞传代后随机分为5组.未处理组:正常培养的HTMC;对照组:正常培养的HTMC+ H2O2(500 μmol·L-1处理1h);PC组:正常培养的HTMC+ H2O2(500 μmol·L-1处理1h) +PC(浓度分别为0.02 g·L-1、0.05 g· L-1、0.10 g· L-1).应用实时荧光定量PCR方法检测线粒体复合物Ⅰ mRNA的表达.结果 与未处理组(1.000 0±0.000 0)相比,0.02 g· L-1 PC组(0.401 3±0.010 3)和0.05 g· L-1 PC组(0.791 5±0.008 5)线粒体复合物Ⅰ mRNA表达差异有统计学意义(均为P<0.01),而0.10g·L-1 PC组(1.043 0 ±0.062 2)差异无统计学意义(P>0.05);与对照组(0.095 0±0.006 5)相比,各PC处理组线粒体复合物Ⅰ mRNA表达均增加,差异均有统计学意义(均为P<0.01);不同浓度PC组间随PC浓度增加线粒体复合物Ⅰ mRNA表达增加,各PC浓度组组间差异有统计学意义(P<0.01).结论 外源性PC可以增加氧化应激HTMC线粒体复合物I mRNA的表达,有较强的抗氧化作用,并在一定范围内随着浓度的增加其抗氧化作用逐渐增强,PC在青光眼的临床治疗中的作用值得进一步研究. 相似文献
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原发性开角型青光眼(primary open angle glaucoma,POAG)是以持续性眼压增高导致视神经损伤为主要临床表现的一种疾病,其发病机制复杂,尚未明确,现阶段临床治疗相对困难。影响眼内压(intraocular pressure,IOP)高低的重要因素是房水引流是否通畅,而房水引流途径中小梁网(trabecular meshwork,TM)起重要调控作用。TM细胞的形态、数量、结构和功能改变均可使房水外流阻力增大,从而导致IOP升高。研究证实诱导多功能干细胞(induced pluripotent stem cells,iPSCs)、骨髓间充质干细胞(bone mesenchymal stem cells,BMSCs)和脂肪干细胞(adipose-derived stem cells,ADSCs)已被用于TM细胞的分化和再生,为POAG小梁网的干细胞替代治疗提供可靠的细胞来源。近年研究发现,小梁网干细胞(trabecular meshwork stem cells,TMSCs)在分化为TM细胞方面具有绝对优势,为细胞移植治疗青光眼提供新的靶向,这标志着干细胞治疗POAG进入一个新纪元,为青光眼治疗带来新的曙光。本文将对不同种类干细胞的小梁网移植进行综述,为细胞移植治疗POAG提供新思路。 相似文献
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外伤性房角后退型青光眼小梁网超微结构的改变 总被引:3,自引:0,他引:3
本文报道三例外伤性房角后退型青光眼患者,应用光学显微镜和透射电子显微对其小梁标本进行超微结构的研究。三例标本均可见小梁细胞减少、变性和小梁纤维变性、结构紊乱。我们的研究表明:挫伤后小梁网组织结构的破坏导致房水引液受阻、眼压升高,这是外伤性房角后退型青光眼的主要发病机制。 相似文献
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小梁网细胞外基质与原发性开角型青光眼的病因研究 总被引:2,自引:0,他引:2
小梁网细胞外基质与原发性开角型青光眼的病因研究陈林闻毅颐广州市第二医院眼科(510150)小梁网是小梁细胞贴附于小梁柱上形成的筛网状结构。房水是通过网孔引流的。房水引流通畅与否直接与网孔大小有关。小梁网细胞外基质(ExtracelularMatri... 相似文献
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目的 研究原花青素对H2O2诱导人眼小梁网细胞(human trabecular meshwork cells,HTMC)凋亡及细胞色素C释放的影响.方法 将HTMC进行传代后随机分为5组.未处理组:正常培养的HTMC;对照组:正常培养的HTMC+H2O2(500μmol·L-1处理lh);3个浓度的原花青素组:正常培养的HTMC+H2O2(500 μmol· L-1处理lh)+原花青素(浓度分别为0.02 g·L-1、0.05 g·L-1、0.10g·L-1).使用Annexin V-FITC检测细胞凋亡情况,Western blot检测HTMC胞浆细胞色素C含量.结果 与未处理组相比,对照组及各原花青素组细胞凋亡率均升高,差异均有统计学意义(均为P<0.01).与对照组相比,各原花青素组细胞凋亡率均降低,差异均有统计学意义(均为P<0.01);不同浓度原花青素组间随原花青素浓度增加细胞凋亡率下降,各原花青素组间差异均有统计学意义(均为P<0.01).与未处理组相比,对照组以及0.02 g·L-1和0.05 g· L-1原花青素组细胞色素C的释放均增加,差异均有统计学意义(均为P<0.01);而0.10 g·L-1原花青素组与未处理组相比,差异无统计学意义(P>0.05).与对照组相比,各原花青素组细胞色素C释放均减少,差异均有统计学意义(均为P<0.01).不同浓度原花青素组间随原花青素浓度增加细胞色素C的释放减少,各组间差异均有统计学意义(均为P<0.01).结论 外源性原花青素可以降低氧化应激HTMC的凋亡率,减少细胞色素C的释放,有较强的抗氧化作用,并在一定浓度范围内随着浓度的增加其抗氧化作用逐渐增强. 相似文献
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The trabecular meshwork (TM) region of the eye is exposed to a constant low-level of oxidative insult. The cumulative damage may be the reason behind age-dependent risk for developing primary open angle glaucoma. Chronic and acute effects of hydrogen peroxide (H2O2) on TM endothelial cells include changes in viability, protein synthesis, and cellular adhesion. However, little if anything is known about the immediate effect of H2O2 on the biochemistry of the TM cells and the initial response to oxidative stress. In this report, we have used two-photon excitation autofluorescence (2PAF) to monitor changes to TM cell nicotinamide adenine dinucleotide (NADPH). 2PAF allows non-destructive, real-time analysis of concentration of intracellular NADPH. Coupled to reduced glutathione, NADPH, is a major component in the anti-oxidant defense of TM cells. Cultured human TM cells were monitored for over 30 min in control and H2O2-containing solutions. Peroxide caused both a dose- and time-dependent decrease in NADPH signal. NADPH fluorescence in control and in 4 mM H2O2 solutions showed little attenuation of NADPH signal (4% and 9% respectively). TM cell NADPH fluorescence showed a linear decrease with exposure to 20 mM H2O2 (−29%) and 100 mM H2O2 (37%) after a 30 min exposure. Exposure of TM cells to 500 mM H2O2 caused an exponential decrease in NADPH fluorescence to a final attenuation of 46% of starting intensity. Analysis of individual TM cells indicates that cells with higher initial NADPH fluorescence are more refractive to the apparent loss of viability caused by H2O2 than weakly fluorescing TM cells. We conclude that 2PAF of intracellular NADPH is a valuable tool for studying TM cell metabolism in response to oxidative insult. 相似文献
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Zeynep Aktas¹ Emine Esra Kara Ipek Işik Gonul Murat Hasanreisoglu Merih Onol 《国际眼科杂志》2013,13(6):827-830
AIM: To compare the trabecular meshwork (TM) and iris apoptosis of treated and untreated primary open angle glaucoma (POAG) patients.METHODS: Eight treatment-naive, newly diagnosed (group 1) and 11 medicaly treated (group 2) patients with POAG were included in the study. Each patient underwent a limbus-based trabeculectomy. The TM and peripheral iris specimens were dissected out and were snap-frozen in liquid nitrogen and stored at –80℃ until they were assayed. Apoptosis in each group was assesed by TUNEL method.RESULTS:The mean patient age was 60.6±5.8 years (53-68 years) vs 58.9±8.9 years (47-70 years) in group 1 and group 2 (P=0.859). The mean treatment time in group 2 was 22.2±7.3 months (12-34 months). Apoptotic indexes in TM and iris were significantly higher in POAG patients using medication (group 2) compared to treatment-naive POAG patients (group 1) (P=0.004, 0.015; respectively).CONCLUSION: Long term administration of topical antiglaucoma medications causes additional toxic effects on TM. 相似文献
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Ozan-Yüksel Tektas 《Experimental eye research》2009,88(4):769-775
The morphology of the trabecular meshwork in three types of open angle glaucoma: primary open angle glaucoma (POAG), corticosteroid-induced glaucoma and pigmentary glaucoma (PG) are described.Ageing is one major risk factor for development of POAG. It is assumed that preexisting age-related changes of the trabecular meshwork (TM) play a role for the development of increased outflow resistance and intraocular pressure (IOP) in various types of glaucoma. These age-related changes in the TM develop concomitant with that of presbyopia. Therefore the functional relationship between ciliary muscle (CM) and TM and the age-related changes in morphology of the outflow system are described first. One main finding in the ageing TM concerns changes of the elastic fiber network and the anterior elastic tendons of the CM. There is an increase in thickness of the sheath of the elastic fibers. Cross-sections through these fibers with their sheath appear as extracellular plaques and were therefore termed “sheath derived plaques” (SD-plaques).Morphologically, the TM changes in POAG resemble that of the ageing TM, but in POAG there is a significant increase in SD-plaques compared to age-matched controls. This increase is due to fine fibrils and other components of the extracellular matrix (ECM) that adhere to the sheaths of the elastic fibers and their connections to the inner wall endothelium. In POAG eyes there is also a marked loss of TM cells, at places leading to fusion and thickening of trabecular lamellae.In steroid-induced glaucoma there is also an increase in fine fibrillar material in the subendothelial region of SC. In contrast to POAG eyes these fibrils do not adhere to the sheath of the elastic fibers but are deposited underneath the inner wall endothelium. The main finding in steroid-induced glaucoma is an accumulation of basement membrane-like material staining for type IV collagen. These accumulations are found throughout all layers of the TM.In pigmentary glaucoma loss of cells was more prominent than in POAG eyes. Presumably, this cell loss occurs after overload of TM cells with pigment granules. Denuded TM lamellae fuse and the TM collapses. In the subendothelial region of these collapsed TM areas an increase in ECM presumably due to underperfusion was observed. At other places SC was occluded and the cribriform region appeared disorganized. In most parts of the circumference of the eye, the TM cells contained pigment granules. Occlusion of TM spaces by pigment granules or cells loaden with pigment was not seen in eyes with PG. 相似文献
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Interaction of primary human trabecular meshwork cells with metal alloy candidates for microinvasive glaucoma surgery
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Wan Wendy Wang BMSc Kelsey A Watson BMSc S Jeffrey Dixon DDS PhD Hong Liu Amin S Rizkalla PhD PEng Cindy ML Hutnik MD PhD 《Clinical & experimental ophthalmology》2017,45(5):520-528