Leung C K S, Lindsey J D, Chen L, Liu Q, Weinreb R N
Hamilton Glaucoma Center, University of California, San Diego, La Jolla, CA 92093-0946, USA.
Br J Ophthalmol. 2009 Jul;93(7):964-8. doi: 10.1136/bjo.2008.150482. Epub 2009 Feb 17.
To longitudinally investigate retinal ganglion cell (RGC) expression of Thy-1, a cell-surface glycoprotein specifically expressed in RGCs, with a blue-light confocal scanning laser ophthalmoscope, following retinal ischaemia induced by acute elevation of intraocular pressure.
A blue-light confocal scanning laser ophthalmoscope (bCSLO, 460 nm excitation and 490 nm detection) was used to image Thy1-cyan fluorescent protein (CFP) mice before and weekly for 4 weeks after transiently elevating the intraocular pressure to 115 mm Hg for 45 min (n = 4) or 90 min (n = 5) to induce ischaemic injury. Corresponding retinal areas before and after the intraocular pressure (IOP) elevation, during the period of ischaemic reperfusion, were compared, and the fluorescent spots (Thy-1 expressing RGCs) were counted. The longitudinal profile of CFP-expressing RGCs was modelled with a linear regression equation. The spatial distribution of RGC damage was analysed in the superior, nasal, inferior and temporal quadrants of the retina.
No significant change was found at 4 weeks after 45 min of IOP elevation (n = 4, p = 0.465). The average RGC densities before and 4 weeks after IOP elevation were 1660 (SD 242) cells/mm2 and 1624 (209) cells/mm2, respectively. However, significant loss of CFP-expressing RGCs was detected at 1 week following 90 min of IOP elevation (n = 5, p<0.001). After this initial RGC loss, no significant change was detected subsequently. The proportion of RGC fluorescence remaining was variable and ranged from 14.5% to 79.5% at 4 weeks after the IOP elevation. The average RGC densities before and 4 weeks after IOP elevation were 1443 (162) cells/mm2 and 680 (385) cells/mm2, respectively. Diffuse loss of fluorescent RGCs was observed in the spatial distribution analysis.
The longitudinal profile of Thy-1 expressing RGC fluorescence loss after ischaemic injury is non-progressive and unrelated to the duration of reperfusion.
使用蓝光共聚焦扫描激光眼科显微镜，纵向研究在急性眼压升高诱导视网膜缺血后，视网膜神经节细胞（RGC）中特异性表达的细胞表面糖蛋白Thy-1的表达情况。
使用蓝光共聚焦扫描激光眼科显微镜（bCSLO，激发波长460 nm，检测波长490 nm），在将眼压短暂升高至115 mmHg持续45分钟（n = 4）或90分钟（n = 5）以诱导缺血性损伤之前以及之后每周一次，共4周，对Thy1-青色荧光蛋白（CFP）小鼠进行成像。比较眼压（IOP）升高前后以及缺血再灌注期间相应的视网膜区域，并对荧光斑点（表达Thy-1的RGC）进行计数。用线性回归方程对表达CFP的RGC的纵向变化情况进行建模。在视网膜的上、鼻、下和颞象限分析RGC损伤的空间分布。
眼压升高45分钟后4周未发现显著变化（n = 4，p = 0.465）。眼压升高前后及4周后的平均RGC密度分别为1660（标准差242）个细胞/mm²和1624（209）个细胞/mm²。然而，眼压升高90分钟后1周检测到表达CFP的RGC显著减少（n = 5，p<0.001）。在最初的RGC损失之后，随后未检测到显著变化。眼压升高4周后，RGC荧光残留比例各不相同，范围为14.5%至79.5%。眼压升高前后及4周后的平均RGC密度分别为1443（162）个细胞/mm²和680（385）个细胞/mm²。在空间分布分析中观察到荧光RGC的弥漫性损失。
缺血性损伤后表达Thy-1的RGC荧光损失的纵向变化情况是非进行性的，且与再灌注持续时间无关。
