Divergent distribution in vascular and avascular mammalian retinae links neuroglobin to cellular respiration
Divergent distribution in vascular and avascular mammalian retinae links neuroglobin to cellular respiration
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DOI：
10.1074/jbc.m501338200
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发表时间：
2005-05-27
影响因子：
4.8
通讯作者：
Burmester, T
中科院分区：
文献类型：
--
作者：
Bentmann, A;Schmidt, M;Burmester, T
脊椎动物视网膜的视觉功能依赖于充足的氧气供应。脑红蛋白是一种呼吸蛋白质，被认为在神经细胞的氧稳态中起重要作用。为了进一步了解其功能，我们比较了神经红蛋白和线粒体在血管和无血管哺乳动物视网膜中的分布。在小鼠和大鼠的血管视网膜中，氧气由外部脉络膜、视网膜深部和内部毛细血管供应。我们发现，在这种类型的视网膜，线粒体集中在感光细胞的内节，外，内丛状层，和神经节细胞层。这些区域与氧气消耗发生且脑红蛋白含量高的区域相同。在豚鼠无血管视网膜中，视网膜深部和内部毛细血管缺失。因此，只有邻近脉络膜毛细血管的光感受器的内节显示氧化代谢。我们证明，在豚鼠的视网膜神经红蛋白和线粒体都局限于这一层。我们的研究结果清楚地表明了脑红蛋白和线粒体的关联，从而支持了脑红蛋白是一种呼吸蛋白质，为呼吸链提供氧气的假设。
The visual function of the vertebrate retina relies on sufficient supply with oxygen. Neuroglobin is a respiratory protein thought to play an essential role in oxygen homeostasis of neuronal cells. For further understanding of its function, we compared the distribution of neuroglobin and mitochondria in both vascular and avascular mammalian retinae. In the vascular retinae of mouse and rat, oxygen is supplied by the outer choroidal, deep retinal, and inner capillaries. We show that in this type of retina, mitochondria are concentrated in the inner segments of photoreceptor cells, the outer and the inner plexiform layers, and the ganglion cell layer. These are the same regions in which oxygen consumption takes place and in which neuroglobin is present at high levels. In the avascular retina of guinea pig the deep retinal and inner capillaries are absent. Therefore, only the inner segments of the photoreceptors adjacent to choroidal capillaries display an oxidative metabolism. We demonstrate that in the retina of guinea pigs both neuroglobin and mitochondria are restricted to this layer. Our results clearly demonstrate an association of neuroglobin and mitochondria, thus supporting the hypothesis that neuroglobin is a respiratory protein that supplies oxygen to the respiratory chain.