Sublethal Photic Stress and the Motility of RPE Phagosomes and Melanosomes
Sublethal Photic Stress and the Motility of RPE Phagosomes and Melanosomes
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DOI：
10.1167/iovs.08-2671
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发表时间：
2009-04-01
影响因子：
4.4
通讯作者：
Zareba, Mariusz
中科院分区：
文献类型：
--
作者：
Burke, Janice M.;Zareba, Mariusz
目的.为了确定是否亚致死氧化应激视网膜色素上皮细胞可见光处理影响细胞器的移位，特别是吞噬体和黑素体。分离的猪黑素体被ARPE-19细胞吞噬，然后用蓝光处理培养物以通过整个细胞质中的内源性视网膜色素上皮（RPE）发色团产生活性氧中间体（ROI）。其他黑素体在吞噬作用之前预先装载有光敏剂，并且对细胞进行光处理以在颗粒表面特异性地产生ROI。通过活细胞成像分析吞噬体运动。还分析了吞噬黑乳胶珠，吞噬黑素体预处理，以模拟年龄相关的黑色素光漂白，和内源性RPE黑素体在猪视网膜色素上皮细胞的原代培养物。亚致死蓝光处理减缓了一些，但不是全部，吞噬黑素体的运动。所有的吞噬体减缓感兴趣区附近的细胞器通过光敏反应产生。黑素体光漂白，使颗粒更具光反应性，增加了蓝光的影响。蓝光处理还减慢了含有乳胶珠和内源性色素颗粒的吞噬体的运动。蓝光诱导的应激损害RPE细胞中的吞噬体运动，但对单个细胞器的影响不同，这表明轻度氧化损伤的影响随亚细胞位置而变化。运动减慢的机制至少部分是局部的，因为细胞器子域中的光敏反应可以诱导运动减慢，并且当吞噬体内容物具有光反应性时，运动减慢的幅度更大。光应力可能会损害RPE细胞器的运动和定位，这将对维持功能有效的亚细胞组织产生广泛的影响。（Invest Ophthalmol维斯科学。2009; 50：1940-1947）DOI：10.1167/iovs.08-2671
PURPOSE. To determine whether sublethal oxidative stress to the retinal pigment epithelium by visible light treatment affects the translocation of organelles, notably phagosomes and melanosomes.METHODS. Isolated porcine melanosomes were phagocytized by ARPE-19 cells, then cultures were treated with blue light to generate reactive oxygen intermediates (ROIs) by endogenous retinal pigment epithelial (RPE) chromophores throughout the cytoplasm. Other melanosomes were preloaded with a photosensitizer before phagocytosis, and cells were light treated to generate ROIs specifically at the granule surface. Phagosome movement was analyzed by live cell imaging. Also analyzed were phagocytized black latex beads, phagocytized melanosomes pretreated to simulate age-related melanin photobleaching, and endogenous RPE melanosomes in primary cultures of porcine retinal pigment epithelium.RESULTS. Sublethal blue light treatment slowed the movement of some, but not all, phagocytized melanosomes. All phagosomes slowed when ROIs were generated near the organelles through a photosensitized reaction. Melanosome photobleaching, which makes granules more photoreactive, increased the effects of blue light. Blue light treatment also slowed the motility of phagosomes containing latex beads and endogenous pigment granules.CONCLUSIONS. Blue light-induced stress impairs phagosome motility in RPE cells but affects individual organelles differently, suggesting that the effects of mild oxidative injury vary with subcellular location. The mechanisms underlying slowed motility are at least partially local because slowing can be induced by a photosensitized reaction in the subdomain of the organelle and the magnitude of the slowing is greater when the phagosome contents are photoreactive. Photic stress may impair the movement and positioning of RPE organelles, which would have widespread consequences for maintaining a functionally efficient subcellular organization. (Invest Ophthalmol Vis Sci. 2009; 50: 1940-1947) DOI: 10.1167/iovs.08-2671