Fatty acid oxidation and photoreceptor metabolic needs.
Fatty acid oxidation and photoreceptor metabolic needs.
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DOI：
10.1194/jlr.tr120000618
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发表时间：
2021
影响因子：
6.5
通讯作者：
Smith LEH
中科院分区：
文献类型：
--
作者：
Fu Z;Kern TS;Hellström A;Smith LEH
光感受器具有高能量需求和高密度的线粒体，其通过燃料底物的氧化磷酸化（OXPHOS）产生ATP。虽然葡萄糖是CNS脑神经元的主要燃料，但在光感受器（也是CNS）中，大多数葡萄糖不通过OXPHOS代谢，而是通过有氧糖酵解代谢成乳酸。近六十年来，感光细胞线粒体的主要燃料来源仍然不清楚。与其他具有高代谢率的组织（如心脏和骨骼肌）类似，最近发现光感受器通过OXPHOS代谢脂肪酸（棕榈酸酯）。脂质进入光感受器的破坏导致细胞外脂质积累，抑制葡萄糖转运蛋白的表达，和双重脂质/葡萄糖燃料短缺。调节脂质代谢有助于恢复感光功能。然而，作为视网膜能量来源的脂质类型的进一步阐明，与其他燃料途径的代谢相互作用，以及视网膜细胞之间的串扰，以提供能量给光感受器还没有完全理解。本文就光感受器的能量需求和来源以及光感受器代谢的研究进展作一综述。
Photoreceptors have high energy demands and a high density of mitochondria that produce ATP through oxidative phosphorylation (OXPHOS) of fuel substrates. Although glucose is the major fuel for CNS brain neurons, in photoreceptors (also CNS), most glucose is not metabolized through OXPHOS but is instead metabolized into lactate by aerobic glycolysis. The major fuel sources for photoreceptor mitochondria remained unclear for almost six decades. Similar to other tissues (like heart and skeletal muscle) with high metabolic rates, photoreceptors were recently found to metabolize fatty acids (palmitate) through OXPHOS. Disruption of lipid entry into photoreceptors leads to extracellular lipid accumulation, suppressed glucose transporter expression, and a duel lipid/glucose fuel shortage. Modulation of lipid metabolism helps restore photoreceptor function. However, further elucidation of the types of lipids used as retinal energy sources, the metabolic interaction with other fuel pathways, as well as the cross-talk among retinal cells to provide energy to photoreceptors is not fully understood. In this review, we will focus on the current understanding of photoreceptor energy demand and sources, and potential future investigations of photoreceptor metabolism.