PDF(Pubmed)
Abstract：
The retinal pigment epithelium (RPE) is an essential component of the retina that plays multiple roles required to support visual function. These include light onset- and circadian rhythm-dependent tasks, such as daily phagocytosis of photoreceptor outer segments. Mitochondria provide energy to the highly specialized and energy-dependent RPE. In this study, we examined the positioning of mitochondria and how this is influenced by the onset of light. We identified a population of mitochondria that are tethered to the basal plasma membrane pre- and post-light onset. Following light onset, mitochondria redistributed apically and interacted with melanosomes and phagosomes. In a choroideremia mouse model that has regions of the RPE with disrupted or lost infolding of the plasma membrane, the positionings of only the non-tethered mitochondria were affected. This provides evidence that the tethering of mitochondria to the plasma membrane plays an important role that is maintained under these disease conditions. Our work shows that there are subpopulations of RPE mitochondria based on their positioning after light onset. It is likely they play distinct roles in the RPE that are needed to fulfil the changing cellular demands throughout the day.
摘要：
视网膜色素上皮（RPE）是视网膜的重要组成部分，起着支持视觉功能所需的多种作用。这些包括光连续和昼夜节律相关的任务，例如光感受器外节的每日吞噬作用。线粒体为高度专业化和能量依赖性RPE提供能量。在这项研究中,我们检查了线粒体的位置，以及它是如何受到光的影响的。我们确定了在轻度发作前后与基底质膜相连的线粒体群体。轻度发作后，线粒体在顶部重新分布并与黑色素体和吞噬体相互作用。在无脉络膜血症小鼠模型中，RPE区域的质膜内折叠被破坏或丢失，只有非束缚线粒体的位置受到影响。这提供了线粒体与质膜的连接在这些疾病条件下维持的重要作用的证据。我们的工作表明，根据光照后的定位，存在RPE线粒体亚群。它们很可能在RPE中扮演不同的角色，这是全天满足不断变化的蜂窝需求所必需的。
