As the aqueous humor leaves the eye, it first passes through the trabecular meshwork （TM）. Increased flow resistance in this region causes elevation of intraocular pressure （IOP）, which leads to the occurrence of ...As the aqueous humor leaves the eye, it first passes through the trabecular meshwork （TM）. Increased flow resistance in this region causes elevation of intraocular pressure （IOP）, which leads to the occurrence of glaucoma. To quantitatively evaluate the effect of high IOP on the configuration and hydraulic permeability of the TM, second harmonic generation （SHG） microscopy was used to image the microstructures of the TM and adjacent tissues in control （normal） and high IOP conditions. Enucleated rabbit eyes were perfused at a pressure of 60 mmHg to achieve the high lOP. Through the anterior chamber of the eye, in situ images were obtained from different depths beneath the surface of the TM. Porosity and specific surface area of the TM in control and high IOP conditions were then calculated to estimate the effect of the high pressure on the permeability of tissue in different depths. We further photographed the histological sections of the TM and compared the in situ images. The following results were obtained in the control condition, where the region of depth was less than 55 μm with crossed branching beams and large pores in the superficial TM. The deeper meshwork is a silk-like tissue with abundant fluorescence separating the small size of pores. The total thickness of pathway tissues composed of TM and juxtacanalicular （JCT） is more than 100 p.m. After putting a high pressure on the inner wall of the eye, the TM region progressively collapses and decreases to be less than 40 μm. Fibers of the TM became dense, and the porosity at 34 μm in the high IOP condition is comparable to that at 105 μm in the control condition. As a consequent result, the permeability of the superficial TM decreases rapidly from 120 μm2 to 49.6 μm2 and that of deeper TM decreases from 1.66 μm2 to 0.57 μm2. Heterogeneity reflected by descent in permeability reduces from 12.4 μm of the control condition to 3.74 μm of the high IOP condition. The persistently high IOP makes the TM region collapse from its normal state, in which the collagen fibers of the TM are arranged in regular to maintain the physiological permeability of the outflow pathway. In the scope of pathologically high IOP, the microstructure of the TM is sensitive to pressure and hydraulic permeability can be significantly affected by IOP.展开更多
目的通过观察糖基化终末产物(advanced glycation end products,AGE)对体外培养牛眼小梁细胞凋亡的影响,研究AGE与原发性开角型青光眼(primary open angle glaucoma,POAG)之间的关系,进一步探讨其发病机制。方法体外培养牛眼小梁细胞,...目的通过观察糖基化终末产物(advanced glycation end products,AGE)对体外培养牛眼小梁细胞凋亡的影响,研究AGE与原发性开角型青光眼(primary open angle glaucoma,POAG)之间的关系,进一步探讨其发病机制。方法体外培养牛眼小梁细胞,通过形态学观察和神经元特异性烯醇化酶染色对培养的细胞进行鉴定。将第3代小梁细胞接种于6孔培养板,在培养基中加入不同浓度(0μg·mL-1、50μg·mL-1、100μg·mL-1、200μg·mL-1)的AGE-BSA培养96 h。终浓度(200μg·mL-1)的AGE-BSA培养液处理细胞不同时间(48 h、72 h、96h)。应用流式细胞仪检测小梁细胞凋亡率;活性氧荧光探针2’,7’-二氯荧光黄双乙酸盐检测细胞内活性氧(ROS)水平。结果 50μg·mL-1、100μg·mL-1、200μg·mL-1AGE-BSA作用96h后细胞凋亡率分别为(5.60±0.25)%、(9.57±0.08)%、(17.68±0.21)%,与对照组(0μg·mL-1AGE-BSA)细胞凋亡率(4.45±0.12)%相比均明显增高,且差异均有统计学意义(均为P<0.05);200μg·mL-1AGE-BSA作用细胞48 h、72 h、96 h后凋亡率分别为(10.51±0.28)%、(13.47±0.42)%、(17.68±0.21)%,与对照组相比也均明显增高,差异均有统计学意义(均为P<0.05)。与对照组比较,AGE-BSA处理后细胞内ROS水平显著提高,差异有统计学意义(P<0.05),BSA组差异无统计学意义(P>0.05)。结论在体外培养的条件下,AGE可能通过刺激牛眼小梁细胞产生大量ROS介导小梁细胞凋亡。展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.31070840,10802053,and 81201123)the Natural Science Foundation of Beijing,China(Grant No.3122010)+2 种基金the Natural Science Foundation of Guangdong Province,China(Grant No.S2012040006576)the Shenzhen Science and Technology Innovation Committee,China(Grant No.KQCX20120816155352228)the Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality,China(Grant No.PHR201110506)
文摘As the aqueous humor leaves the eye, it first passes through the trabecular meshwork （TM）. Increased flow resistance in this region causes elevation of intraocular pressure （IOP）, which leads to the occurrence of glaucoma. To quantitatively evaluate the effect of high IOP on the configuration and hydraulic permeability of the TM, second harmonic generation （SHG） microscopy was used to image the microstructures of the TM and adjacent tissues in control （normal） and high IOP conditions. Enucleated rabbit eyes were perfused at a pressure of 60 mmHg to achieve the high lOP. Through the anterior chamber of the eye, in situ images were obtained from different depths beneath the surface of the TM. Porosity and specific surface area of the TM in control and high IOP conditions were then calculated to estimate the effect of the high pressure on the permeability of tissue in different depths. We further photographed the histological sections of the TM and compared the in situ images. The following results were obtained in the control condition, where the region of depth was less than 55 μm with crossed branching beams and large pores in the superficial TM. The deeper meshwork is a silk-like tissue with abundant fluorescence separating the small size of pores. The total thickness of pathway tissues composed of TM and juxtacanalicular （JCT） is more than 100 p.m. After putting a high pressure on the inner wall of the eye, the TM region progressively collapses and decreases to be less than 40 μm. Fibers of the TM became dense, and the porosity at 34 μm in the high IOP condition is comparable to that at 105 μm in the control condition. As a consequent result, the permeability of the superficial TM decreases rapidly from 120 μm2 to 49.6 μm2 and that of deeper TM decreases from 1.66 μm2 to 0.57 μm2. Heterogeneity reflected by descent in permeability reduces from 12.4 μm of the control condition to 3.74 μm of the high IOP condition. The persistently high IOP makes the TM region collapse from its normal state, in which the collagen fibers of the TM are arranged in regular to maintain the physiological permeability of the outflow pathway. In the scope of pathologically high IOP, the microstructure of the TM is sensitive to pressure and hydraulic permeability can be significantly affected by IOP.
