Braunger Barbara M, Ademoglu Bahar, Koschade Sebastian E, Fuchshofer Rudolf, Gabelt B'Ann T, Kiland Julie A, Hennes-Beann Elizabeth A, Brunner Kevin G, Kaufman Paul L, Tamm Ernst R
Institute of Human Anatomy and Embryology, University of Regensburg, Regensburg, Germany.
Department of Ophthalmology & Visual Sciences, University of Wisconsin School of Medicine & Public Health, Madison, Wisconsin, United States.
Invest Ophthalmol Vis Sci. 2014 Oct 16;55(11):7499-507. doi: 10.1167/iovs.14-14872.
To identify stem cells in the chamber angle of the monkey eye by detection of 5-bromo-2'-deoxyuridine (BrdU) long-term retention.
Four cynomolgus monkeys were treated with BrdU via subcutaneous pumps for 4 weeks. The eyes of two animals were processed immediately thereafter (group 1) while in the other animals, BrdU treatment was discontinued for 4 weeks to allow identification of cells with long-term BrdU retention (group 2). The number of BrdU-positive nuclei was quantified, and the cells were characterized by immunohistochemistry and transmission electron microscopy (TEM).
The number of BrdU-positive cells was higher at Schwalbe's line covering the peripheral end of Descemet's membrane than in Schlemm's canal (SC) endothelium, trabecular meshwork (TM), and scleral spur (SS). Labeling with BrdU in SC, TM, and SS was less intense and the number of labeled cells was smaller in group 2 than in group 1. In contrast, in cells of Schwalbe's line the intensity of BrdU staining and the number of BrdU-positive cells was similar when group 1 and 2 monkeys were compared with each other, indicating long-term BrdU retention. Cells that were BrdU-positive in Schwalbe's line region stained for the stem cell marker OCT4. Details of a stem cell niche in Schwalbe's line region were identified by TEM.
We provide evidence for a niche in the Schwalbe's line region harboring cells with long-term BrdU retention and OCT4 immunoreactivity. The cells likely constitute a population of adult stem cells with the capability to compensate for the loss of TM and/or corneal endothelial cells.
通过检测5-溴-2'-脱氧尿苷（BrdU）的长期留存来鉴定猴眼房角中的干细胞。
对4只食蟹猴通过皮下泵给予BrdU治疗4周。之后立即对其中2只动物的眼睛进行处理（第1组），而在另外的动物中，停止BrdU治疗4周以鉴定具有长期BrdU留存的细胞（第2组）。对BrdU阳性细胞核的数量进行定量，并通过免疫组织化学和透射电子显微镜（TEM）对细胞进行表征。
覆盖Descemet膜外周端的Schwalbe线处的BrdU阳性细胞数量高于施莱姆管（SC）内皮、小梁网（TM）和巩膜突（SS）中的数量。第2组中SC、TM和SS的BrdU标记强度较低且标记细胞数量少于第1组。相比之下，比较第1组和第2组猴子时，Schwalbe线细胞中的BrdU染色强度和BrdU阳性细胞数量相似，表明BrdU长期留存。Schwalbe线区域中BrdU阳性的细胞对干细胞标志物OCT4染色。通过TEM确定了Schwalbe线区域干细胞龛的细节。
我们提供了证据，证明Schwalbe线区域存在一个龛，其中含有具有长期BrdU留存和OCT4免疫反应性的细胞。这些细胞可能构成了一群成年干细胞，有能力补偿TM和/或角膜内皮细胞的损失。
