Pigment Epithelium-Derived Factor Regulates Glutamine Synthetase and L-Glutamate/L-Aspartate Transporter in Retinas with Oxygen-induced Retinopathy
Pigment Epithelium-Derived Factor Regulates Glutamine Synthetase and L-Glutamate/L-Aspartate Transporter in Retinas with Oxygen-induced Retinopathy
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色素上皮衍生因子调节氧诱导性视网膜病视网膜中的谷氨酰胺合成酶和 L-谷氨酸/L-天冬氨酸转运蛋白
DOI：
10.3109/02713683.2014.990639
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发表时间：
2015-01-01
影响因子：
2
通讯作者：
Shen, Xi
中科院分区：
文献类型：
--
作者：
Wang, Yanuo;Lu, Qing;Shen, Xi
目的：Muller细胞的主要功能是调节谷氨酸水平，但这些细胞在氧诱导的视网膜病变中受损。本研究旨在探讨缺氧条件下色素上皮衍生因子（PEDF）在调节视网膜谷氨酸水平中的作用。材料与方法：将1周龄C57BL/6J小鼠置于75%氧环境5 d，再置于室内空气中5 d，建立氧致视网膜病变（OIR）小鼠模型。小鼠分别在出生后12和14天玻璃体内注射2 μ g PEDF或对照物。采用抗白细胞介素-1 β (IL-1 β)抗体（IL-1ab）中和IL-1 β的活性，分别在小鼠的P12和P14上玻璃体内注射500 ng IL-1ab或对照物。在P17时，对小鼠实施安乐死，并将其眼睛去核。检测不同处理视网膜组织中IL-1 β、谷氨酰胺合成酶（GS）和l -谷氨酸/天冬氨酸转运蛋白（GLAST）的表达水平。此外，野生型C57BL/6J小鼠接受玻璃体内注射IL-1 β或PEDF。24 h后，检测视网膜中GS和GLAST的表达。采用高效液相色谱法测定不同处理视网膜中谷氨酸的浓度。结果：大鼠视网膜中IL-1 β表达升高，谷氨酸水平升高，GS和GLAST表达降低。PEDF可改善OIR小鼠视网膜的特征性变化。通过给予IL-1ab来中和IL-1 β，增加了视网膜中GS和GLAST的表达。此外，在正常小鼠视网膜玻璃体内注射PEDF后，IL-1 β对GS和GLAST表达以及不平衡谷氨酸水平的影响被抑制。结论：提示缺氧条件下，PEDF可能通过抑制IL-1 β的抗炎作用，上调GS和GLAST的表达，降低谷氨酸水平，这些功能可能与PEDF的神经保护作用有关。
Purpose: A predominant function of Muller cells is to regulate glutamate levels, but these cells are compromised in oxygen-induced retinopathy. The aim of this study was to investigate the role of pigment epithelium-derived factor (PEDF) in regulating glutamate levels in retina under hypoxia.Materials and methods: One-week-old C57BL/6J mice were exposed to 75% oxygen for 5 days and then kept in room air for another 5 days to establish the oxygen-induced retinopathy (OIR) mouse model. Mice received intravitreous injections of 2 mu g PEDF or vehicle on postnatal (P) 12 and P14, respectively. Antibody against interleukin-1Beta (IL-1 beta) (IL-1ab) was used to neutralize the activity of IL-1 beta, mice received intravitreous injections of 500 ng IL-1ab or vehicle on P12 and P14, respectively, too. At P17, the mice were euthanized and their eyes were enucleated. The expression levels of IL-1 beta, glutamine synthetase (GS) and L-glutamate/Laspartate transporter (GLAST) in retinas with different treatments were detected. In addition, wild-type C57BL/6J mice received intravitreous injections of IL-1 beta or PEDF. After 24 h, the expression of GS and GLAST in the retinas was also detected. Furthermore, high-performance liquid chromatography (HPLC) was performed to determine the glutamate concentrations in retinas with different treatments.Results: The expression of IL-1 beta and levels of glutamate were increased in retinas with OIR, while the expression of GS and GLAST was decreased. Administration of PEDF ameliorated the characteristic changes in retinas of OIR mice. And neutralization of IL-1 beta by administration of IL-1ab increased GS and GLAST expression in retinas with OIR. Moreover, the effects of IL-1 beta on GS and GLAST expression and unbalanced glutamate levels were inhibited after receiving intravitreous injections of PEDF in retinas of normal mice.Conclusions: These results suggested that PEDF might up-regulate GS and GLAST expression and decrease glutamate levels by suppressing the role of IL-1 beta as an anti-inflammatory factor under hypoxia, and these functions may underlie the neuroprotective effects of PEDF.