Nakazawa Toru, Takeda Masumi, Lewis Geoffrey P, Cho Kin-Sang, Jiao Jianwei, Wilhelmsson Ulrika, Fisher Steven K, Pekny Milos, Chen Dong F, Miller Joan W
Angiogenesis Laboratory, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA.
Invest Ophthalmol Vis Sci. 2007 Jun;48(6):2760-8. doi: 10.1167/iovs.06-1398.
To characterize the reactions of retinal glial cells (astrocytes and Müller cells) to retinal injury in mice that lack glial fibrillary acidic protein (GFAP) and vimentin (GFAP-/-Vim-/-) and to determine the role of glial cells in retinal detachment (RD)-induced photoreceptor degeneration.
RD was induced by subretinal injection of sodium hyaluronate in adult wild-type (WT) and GFAP-/-Vim-/- mice. Astroglial reaction and subsequent monocyte recruitment were quantified by measuring extracellular signal-regulated kinase (Erk) and c-fos activation and the level of expression of chemokine monocyte chemoattractant protein (MCP)-1 and by counting monocytes/microglia in the detached retinas. Immunohistochemistry, immunoblotting, real-time quantitative polymerase chain reaction (PCR), and enzyme-linked immunosorbent assay (ELISA) were used. RD-induced photoreceptor degeneration was assessed by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) and measurement of outer nuclear layer (ONL) thickness.
RD-induced reactive gliosis, characterized by GFAP and vimentin upregulation, Erk and c-fos activation, MCP-1 induction, and increased monocyte recruitment in WT mice. Absence of GFAP and vimentin effectively attenuated reactive responses of retinal glial cells and monocyte infiltration. As a result, detached retinas of GFAP-/-Vim-/- mice exhibited significantly reduced numbers of TUNEL-positive photoreceptor cells and increased ONL thickness compared with those of WT mice.
The absence of GFAP and vimentin attenuates RD-induced reactive gliosis and, subsequently, limits photoreceptor degeneration. Results of this study indicate that reactive retinal glial cells contribute critically to retinal damage induced by RD and provide a new avenue for limiting photoreceptor degeneration associated with RD and other retinal diseases or damage.
表征缺乏胶质纤维酸性蛋白（GFAP）和波形蛋白（GFAP-/-Vim-/-）的小鼠视网膜胶质细胞（星形胶质细胞和穆勒细胞）对视网膜损伤的反应，并确定胶质细胞在视网膜脱离（RD）诱导的光感受器变性中的作用。
通过在成年野生型（WT）和GFAP-/-Vim-/-小鼠的视网膜下注射透明质酸钠诱导RD。通过测量细胞外信号调节激酶（Erk）和c-fos激活、趋化因子单核细胞趋化蛋白（MCP）-1的表达水平以及计数脱离视网膜中的单核细胞/小胶质细胞，对星形胶质细胞反应和随后的单核细胞募集进行定量。使用免疫组织化学、免疫印迹、实时定量聚合酶链反应（PCR）和酶联免疫吸附测定（ELISA）。通过末端脱氧核苷酸转移酶dUTP缺口末端标记（TUNEL）和测量外核层（ONL）厚度评估RD诱导的光感受器变性。
RD诱导的反应性胶质增生，其特征在于WT小鼠中GFAP和波形蛋白上调、Erk和c-fos激活、MCP-1诱导以及单核细胞募集增加。GFAP和波形蛋白的缺失有效减弱了视网膜胶质细胞的反应性反应和单核细胞浸润。结果，与WT小鼠相比，GFAP-/-Vim-/-小鼠的脱离视网膜显示TUNEL阳性光感受器细胞数量显著减少且ONL厚度增加。
GFAP和波形蛋白的缺失减弱了RD诱导的反应性胶质增生，随后限制了光感受器变性。本研究结果表明，反应性视网膜胶质细胞对RD诱导的视网膜损伤起关键作用，并为限制与RD和其他视网膜疾病或损伤相关的光感受器变性提供了新途径。
