Biomechanical strain as a trigger for pore formation in Schlemm's canal endothelial cells.
Biomechanical strain as a trigger for pore formation in Schlemm's canal endothelial cells.
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DOI：
10.1016/j.exer.2014.08.003
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发表时间：
2014-10
影响因子：
3.4
通讯作者：
Overby, Darryl R.
中科院分区：
文献类型：
--
作者：
Braakman, Sietse T.;Pedrigi, Ryan M.;Read, A. Thomas;Smith, James A. E.;Stamer, W. Daniel;Ethier, C. Ross;Overby, Darryl R.
通过常规流出途径的大部分房水必须穿过施累姆氏管（SC）的内壁内皮，可能通过微米尺寸的跨内皮孔。青光眼中SC孔密度降低，可能导致房水流出受阻和眼内压（IOP）升高。孔形成的机制知之甚少，然而，孔经常被观察到附近的圆顶状的细胞外囊称为巨大的空泡（GV），其中显着的生物力学应变作用于SC细胞。我们假设生物力学应变触发SC细胞中的孔形成。为了检验这一假设，从三个非青光眼供体（年龄为34、44和68岁）中分离原代人SC细胞，并将其接种在保持在膜拉伸装置内的胶原包被的弹性膜上。然后将膜暴露于0%、10%或20%等双轴应变，并在应变开始后5分钟将细胞固定。每个膜含有3-4个单独的SC细胞单层作为重复（N = 34个总单层），并通过扫描电子显微镜在12个随机选择的区域（每个单层约65，000 μm2）中评估孔隙。由4名独立的蒙面观察员鉴定和计数孔隙。在所有三种细胞系中，孔密度随着应变而增加（p < 0.010），从0%应变下的87±37个孔/mm 2增加到10%应变下的342±71个孔/mm 2;三种细胞系中的两种显示孔密度在超过10%应变时没有额外增加。跨细胞“I-孔”和细胞旁“B-孔”均随应变而增加（p < 0.038），然而B-孔占孔的大多数（76%）。相比之下，孔径似乎不受应变影响（p = 0.25），I孔（N = 79个孔）的平均直径为0.40 μm，B孔（N = 350个孔）的平均直径为0.67 μm。孔形成似乎是由生物力学应变触发的机械敏感性过程，表明SC细胞具有基于局部生物力学线索调节局部孔密度和内壁内皮的过滤特性的能力。孔形成的分子机制以及它们在青光眼中如何改变可以使用拉伸的SC细胞在体外进行研究。
The bulk of aqueous humor passing through the conventional outflow pathway must cross the inner wall endothelium of Schlemm’s canal (SC), likely through micron-sized transendothelial pores. SC pore density is reduced in glaucoma, possibly contributing to obstructed aqueous humor outflow and elevated intraocular pressure (IOP). Little is known about the mechanisms of pore formation; however, pores are often observed near dome-like cellular outpouchings known as giant vacuoles (GVs) where significant biomechanical strain acts on SC cells. We hypothesize that biomechanical strain triggers pore formation in SC cells. To test this hypothesis, primary human SC cells were isolated from three non-glaucomatous donors (aged 34, 44 and 68), and seeded on collagen-coated elastic membranes held within a membrane stretching device. Membranes were then exposed to 0%, 10% or 20% equibiaxial strain, and the cells were aldehyde-fixed 5 minutes after the onset of strain. Each membrane contained 3–4 separate monolayers of SC cells as replicates (N = 34 total monolayers), and pores were assessed by scanning electron microscopy in 12 randomly selected regions (~65,000 μm2 per monolayer). Pores were identified and counted by four independent masked observers. Pore density increased with strain in all three cell lines (p < 0.010), increasing from 87±37 pores/mm2 at 0% strain to 342±71 at 10% strain; two of the three cell lines showed no additional increase in pore density beyond 10% strain. Transcellular “I-pores” and paracellular “B-pores” both increased with strain (p < 0.038), however B-pores represented the majority (76%) of pores. Pore diameter, in contrast, appeared unaffected by strain (p = 0.25), having a mean diameter of 0.40 μm for I-pores (N = 79 pores) and 0.67 μm for B-pores (N = 350 pores). Pore formation appears to be a mechanosensitive process that is triggered by biomechanical strain, suggesting that SC cells have the ability to modulate local pore density and filtration characteristics of the inner wall endothelium based on local biomechanical cues. The molecular mechanisms of pore formation and how they become altered in glaucoma may be studied in vitro using stretched SC cells.
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影响因子：
6.1
作者：
Haubert, Kathryn;Drier, Tracy;Beebe, David
通讯作者：
Beebe, David
影响因子：
7.8
作者：
Martinelli, Roberta;Kamei, Masataka;Carman, Christopher V.
通讯作者：
Carman, Christopher V.
影响因子：
30.3
作者：
Maddugoda, Madhavi P.;Stefani, Caroline;Lemichez, Emmanuel
通讯作者：
Lemichez, Emmanuel
DOI：
10.1152/ajpcell.1996.271.4.c1400
发表时间：
1996-10-01
影响因子：
5.5
作者：
Lee, AA;Delhaas, T;McCulloch, AD
通讯作者：
McCulloch, AD
影响因子：
10.1
作者：
Olson, DM;Dinerstein, E;Kassem, KR
通讯作者：
Kassem, KR