Synthesis and secretion of hemoglobin by retinal pigment epithelium.
Synthesis and secretion of hemoglobin by retinal pigment epithelium.
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DOI：
10.1167/iovs.07-1372
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发表时间：
2009-04
影响因子：
4.4
通讯作者：
T. Tezel;L. Geng;E. Lato;S. Schaal;Yongqing Liu;D. Dean;J. Klein;H. Kaplan
中科院分区：
文献类型：
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作者：
T. Tezel;L. Geng;E. Lato;S. Schaal;Yongqing Liu;D. Dean;J. Klein;H. Kaplan
目的 证明人视网膜色素上皮 (RPE) 产生血红蛋白。方法 使用 10 只供体眼睛进行蛋白质组学分析，确定血红蛋白是可溶性人类 RPE 蛋白质组的主要成分。使用蛋白质印迹分析、RT-PCR 和免疫细胞化学来确认结果。研究了原代人 RPE 胞质内红细胞特异性蛋白的存在，以排除吞噬作用作为血红蛋白的来源。 ELISA 用于测定人 RPE 细胞的血红蛋白分泌率。研究了人 RPE 的球蛋白 mRNA 表达，并与人成红细胞系和自发转化的人 RPE 细胞系 (ARPE-19) 进行比较。结果。血红蛋白是可溶性人类 RPE 蛋白质组的常规成分。 RT-PCR 和蛋白质印迹分析证实人 RPE 中存在血红蛋白。在人 RPE 胞质中未检测到其他红细胞特异性蛋白质。血红蛋白表达在体外持续七代。人 RPE 珠蛋白表达超过人成红细胞和 ARPE-19 细胞。免疫组织化学显示 RPE 和布鲁赫膜内存在血红蛋白。血红蛋白释放速率经计算为每个细胞每小时 1.9+/-1.2 阿托摩尔。结论 人类 RPE 表达的血红蛋白为理解氧输送到外视网膜提供了新的视角。 RPE-血红蛋白生成功能障碍可能是以中心凹下缺氧和 VEGF 上调为特征的眼部疾病的病理生理学基础，例如年龄相关性黄斑变性和糖尿病性视网膜病变。对 RPE 细胞局部血红蛋白产生的药理学调节将为干扰这些疾病的进程创造新的机会。
PURPOSE To demonstrate the production of hemoglobin by human retinal pigment epithelium (RPE). METHODS Proteomic analysis using 10 donor eyes identified hemoglobin as a major constituent of soluble human RPE proteome. Western blot analysis, RT-PCR, and immunocytochemistry were used to confirm the RESULTS The presence of erythrocyte-specific proteins within primary human RPE cytosol was investigated to rule out phagocytosis as the source of hemoglobin. ELISA was used to determine the rate of hemoglobin secretion from human RPE cells. Globin mRNA expression of human RPE was studied in comparison with a human erythroblast cell line and a spontaneously transformed human RPE cell line (ARPE-19). results. Hemoglobin is a regular constituent of soluble human RPE proteome. RT-PCR and Western blot analysis confirmed the presence of hemoglobin in human RPE. No other erythrocyte-specific proteins were detected within human RPE cytosol. Hemoglobin expression persisted up to seven passages in vitro. Human RPE globin expression exceeded that in human erythroblast and ARPE-19 cells. Immunohistochemistry revealed the presence of hemoglobin within RPE and Bruch's membrane. The hemoglobin release rate was calculated to be 1.9+/-1.2 attomoles per cell per hour. CONCLUSIONS Hemoglobin expression by human RPE brings a new perspective to the understanding of oxygen transport to the outer retina. Malfunction of RPE-hemoglobin production may underlie the pathophysiology of ocular diseases characterized by subfoveal hypoxia and VEGF upregulation, such as age-related macular degeneration and diabetic retinopathy. Pharmacologic modulations of local hemoglobin production in RPE cells will create new opportunities to interfere with the course of these diseases.