Activated Protein C Rescues the Retina from Ischemia-Induced Cell Death
Activated Protein C Rescues the Retina from Ischemia-Induced Cell Death
复制标题
活化的蛋白 C 可将视网膜从缺血引起的细胞死亡中拯救出来。
DOI：
10.1167/iovs.10-5557
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发表时间：
2011-02-01
影响因子：
4.4
通讯作者：
Kamei, Motohiro
中科院分区：
文献类型：
--
作者：
Du, Zhao-Jiang;Yamamoto, Takuhiro;Kamei, Motohiro
目的。在许多眼科疾病中，包括视网膜中央静脉阻塞(CRVO)和糖尿病视网膜病变，缺血会导致严重和持续性的视力丧失。激活的蛋白C(APC)已被证明可以减少脑和肾脏缺血引起的细胞死亡。方法将视网膜色素上皮(RPE)和光感受器细胞分别置于常氧室和缺氧室中，观察APC在体内外对缺氧所致视网膜细胞死亡的修复作用。在缺血前立即给予APC(3~240 mg/m L)处理。孵育后用四甲基偶氮唑盐比色法测定活细胞数。同时检测RPE细胞中caspase-3、-8、-9的活性。结果不同浓度的APC对大鼠视网膜色素上皮细胞(RPE)和感光细胞均有细胞毒性作用，低浓度的APC(0.3~30 mU g/m L)对体外培养的RPE细胞和感光细胞均有明显的保护作用。Caspase-3、-8和-9在缺氧时被激活，但这种激活被APC显著抑制。结论玻璃体腔注射APC可显著减少实验性CRVO诱导的视网膜细胞凋亡，APC可通过阻断caspase-3、-8、-9的活化，在体内外减轻缺血所致的细胞毒性。APC可能是保护视网膜免受缺血的一种有前途的候选者。(投资眼科VS科学。2011年；52：987-993)doi：10.1167/iovs.10-5557
PURPOSE. Ischemia causes severe and persistent visual loss in many eye diseases, including central retinal vein occlusion (CRVO) and diabetic retinopathy. Activated protein C (APC) has been demonstrated to reduce the cell death associated with ischemia in the brain and kidney. This study was performed to examine the ability of APC to rescue hypoxia-induced retinal cell death in vitro and in vivo.METHODS. Retinal pigment epithelium (RPE) and photoreceptor cells were placed in either a normoxic or a hypoxic chamber. Immediately before they were subjected to ischemia, the cultures were treated with APC (3-240 mu g/mL). Incubation was followed by an MTT assay to determine the number of viable cells. The activity of caspase-3, -8, and -9 in RPE cells was also analyzed. Various concentrations of APC were intravitreally injected in a rat CRVO model, followed by TUNEL staining to detect the in vivo effects of APC.RESULTS. Lower concentrations of APC (0.3-30 mu g/mL) showed a cell-protective effect against hypoxia in vitro, whereas higher concentrations (>= 120 mu g/mL) demonstrated cytotoxicity in both RPE and photoreceptor cells. Caspase-3, -8, and -9 were activated when the cells were exposed to hypoxia, but this activation was significantly inhibited by APC. Experimental CRVO-induced retinal cell apoptosis was reduced dramatically by intravitreal injection of APC.CONCLUSIONS. APC can reduce ischemia-induced cytotoxicity both in vitro and in vivo via blocking the activation of caspase-3, -8, and -9. APC may be a promising candidate for protecting the retina from ischemia. (Invest Ophthalmol Vis Sci. 2011;52:987-993) DOI:10.1167/iovs.10-5557