Global changes in optic nerve head gene expression after exposure to elevated intraocular pressure in a rat glaucoma model
Global changes in optic nerve head gene expression after exposure to elevated intraocular pressure in a rat glaucoma model
复制标题
DOI：
10.1167/iovs.06-1282
复制
发表时间：
2007-07-01
影响因子：
4.4
通讯作者：
Morrison, John C.
中科院分区：
文献类型：
--
作者：
Johnson, Elaine C.;Jia, Lijun;Morrison, John C.
目的.在青光眼中，视神经乳头（ONH）是初始损伤的可能部位，而眼内压（IOP）升高是最常见的风险因素。本研究确定了压力损伤ONH的整体基因表达变化。在大鼠中产生单侧持续性IOP升高（青光眼，n = 46）或视神经横断（n = 10）。去除ONH，并对球后视神经进行变性分级。应用cDNA微阵列技术，比较了广泛损伤的脊髓损伤性ONH与其他ONH（n = 6/组）的基因表达。将来自12个阵列的数据标准化，确定基因表达的显著差异，并鉴定显著受影响的基因类别。对于剩余的ONH，按实验条件和损伤程度分组，使用定量逆转录酶-PCR（qPCR）和ANOVA来比较选择的信息水平。微阵列分析确定了2000多个显著调控的基因。其中225个基因的变化超过两倍。受影响最显著的基因类别是细胞增殖、免疫应答、溶酶体、细胞骨架、细胞外基质和核糖体。ONH细胞结构增加2.7倍证实了青光眼模型细胞增殖。通过qPCR，骨膜蛋白、胶原VI和转化生长因子β 1水平的增加与IOP诱导的损伤程度线性相关。对于cyclinD 1、fibulin 2、tenascin C、TIMP 1和aquaporin-4，相关性显著为非线性，在局灶性损伤时显示最大变化。在ONH中，压力诱导的损伤导致细胞增殖和显著改变的基因表达。对于特定的基因，表达水平的改变最局灶性损伤，这表明进一步的阵列研究可能会确定初始的，潜在的伤害，改变的过程。
PURPOSE. In glaucoma, the optic nerve head (ONH) is the likely site of initial injury and elevated intraocular pressure (IOP) is the best-known risk factor. This study determines global gene expression changes in the pressure- injured ONH.METHODS. Unilateral sustained IOP elevation (glaucoma, n = 46) or optic nerve transection (n = 10) was produced in rats. ONHs were removed, and the retrobulbar optic nerves were graded for degeneration. Gene expression in the glaucomatous ONH with extensive injury was compared with that in the fellow ONH (n = 6/group), by using cDNA microarrays. Data from 12 arrays were normalized, significant differences in gene expression determined, and significantly affected gene classes identified. For the remaining ONH, grouped by experimental condition and degree of injury, quantitative reverse transcriptase-PCR (qPCR) and ANOVA were used to compare selected message levels.RESULTS. Microarray analysis identified more than 2000 significantly regulated genes. For 225 of these genes, the changes were greater than twofold. The most significantly affected gene classes were cell proliferation, immune response, lysosome, cytoskeleton, extracellular matrix, and ribosome. A 2.7-fold increase in ONH cellularity confirmed glaucoma model cell proliferation. By qPCR, increases in levels of periostin, collagen VI, and transforming growth factor beta 1 were linearly correlated to the degree of IOP-induced injury. For cyclinD1, fibulin 2, tenascin C, TIMP1, and aquaporin-4, correlations were significantly nonlinear, displaying maximum change with focal injury.CONCLUSIONS. In the ONH, pressure- induced injury results in cell proliferation and dramatically altered gene expression. For specific genes, expression levels were most altered by focal injury, suggesting that further array studies may identify initial, and potentially injurious, altered processes.