γ-Synuclein as a marker of retinal ganglion cells
γ-Synuclein as a marker of retinal ganglion cells
复制标题
DOI：
--
复制
发表时间：
2008-08
期刊：
影响因子：
2.2
通讯作者：
I. Surgucheva;Alejandra D. Weisman;J. Goldberg;A. Shnyra;A. Surguchov
中科院分区：
文献类型：
--
作者：
I. Surgucheva;Alejandra D. Weisman;J. Goldberg;A. Shnyra;A. Surguchov
目的γ-突触核蛋白是一种在视网膜神经节细胞中高表达的蛋白质，视网膜神经节细胞缺失与青光眼中γ-突触核蛋白基因表达下调有关。在这里，我们询问视网膜中γ-突触核蛋白的表达是否可以被认为是视网膜神经节细胞的特异性标志物。方法采用免疫组织化学方法检测正常人和青光眼患者视网膜组织中γ-Synuclein的表达。用抗Thy1-1单抗序贯免疫纯化的SD大鼠视网膜神经节细胞原代培养、新生大鼠A7永生化视神经星形胶质细胞培养和永生化RGC-5细胞系用免疫荧光和定量RT-PCR方法进行了研究。结果γ-突触核蛋白在人视网膜RGC中高表达，定位于与RGC核标记BRN-3a相邻的胞浆中。视网膜节细胞的轴突在神经纤维层、筛板和球后视神经呈γ-突触核蛋白免疫阳性反应。在青光眼患者的视神经中，轴突肿胀也呈免疫阳性，而在视网膜母细胞瘤患者的视网膜中，NFL染色减弱。在原代培养的大鼠视网膜神经节细胞和永生化培养的视网膜神经节细胞中，γ-突触核蛋白主要定位于核周和细胞突起。在培养的大鼠视网膜细胞中，所有BRN-3a阳性细胞均被γ-突触核蛋白抗体染色，罕见的γ-突触核蛋白阳性细胞未被BRN-3a抗体染色。结论γ突触核蛋白在活体人视网膜节细胞、体外原代大鼠视网膜节细胞和永生化的视网膜节细胞中有选择性和丰富的表达。在病理学上，γ突触核蛋白的丰度在RGC胞体和轴突之间可能不同。BRN-3a和γ-突触核蛋白的一致表达提示γ-突触核蛋白的强表达可被认为是RGC的一个标志。未来的翻译方法可能包括使用γ-突触核蛋白启动子将小干扰RNA或治疗性蛋白特异性地递送到视网膜节细胞。
Purpose Previous studies have described γ-synuclein as a protein highly expressed in retinal ganglion cells (RGCs), and a loss of RGCs correlates with a downregulation of γ-synuclein gene expression in glaucoma. Here we asked whether γ-synuclein expression in the retina can be considered a specific marker of RGCs. Methods γ-Synuclein expression was examined with immunohistochemistry in retinal sections from normal and glaucomatous human eyes. Primary cultures of RGCs from Sprague-Dawley rats purified by sequential immunopanning using a monoclonal antibody to Thy1–1, cultures of A7 immortalized optic nerve astrocytes from newborn rats, and the immortalized RGC-5 cell line were studied using immunofluorescence and quantitative RT–PCR. Results γ-Synuclein was highly expressed in RGCs in the human retina and was localized in cytoplasm adjacent to the RGC nuclear marker, Brn-3a. Axons of RGCs were immunopositive for γ-synuclein in the nerve fiber layer (NFL), the lamina cribrosa and the retrobulbar optic nerve. In the optic nerve of glaucoma patients, axon swellings were likewise immunopositive, whereas in the retina of patients with retinoblastoma, NFL staining appeared reduced. In primary rat RGCs and in immortalized RGC-5 cultures, γ-synuclein was localized predominantly in the perinuclear area and in cell processes. Among rat retinal cells in culture, all Brn-3a positive cells were stained with a γ-synuclein antibody; rare γ-synuclein-positive cells were not stained by the Brn-3a antibody. Conclusions γ-Synuclein is selectively and abundantly expressed in human RGCs in vivo, primary rat RGCs in vitro, and immortalized RGC-5 cells. In pathology, γ-synuclein abundance may vary between RGC somas and axons. Coincident Brn-3a and γ-synuclein expression suggests that strong γ-synuclein expression can be considered a marker of RGCs. Future translational approaches might include using a γ-synuclein promoter for the specific delivery of siRNA or therapeutic proteins to RGCs.