Fructose metabolism in the cerebellum.
Fructose metabolism in the cerebellum.
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小脑中的果糖代谢。
DOI：
10.1080/14734220601064759
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Tolan,DeanR
中科院分区：
文献类型：
--
作者：
Funari,VincentA;Crandall,JamesE;Tolan,DeanR
在正常生理条件下，大脑仅利用少量碳源作为能量。最近，越来越多的分子和生化证据表明其他碳源，包括果糖，可能在神经能量学中发挥作用。果糖是西方文明中排名第一的商业甜味剂，大量果糖是有毒的，但果糖代谢的特征仍然相对较少。据称，果糖通过两种途径代谢：1-磷酸果糖途径和/或6-磷酸果糖途径。许多早期代谢研究无法清楚地区分这两种途径中哪一种占主导地位，也无法区分不同组织中哪些细胞类型能够进行果糖代谢。此外，缺乏良好的生理模型，饮食引起的许多组织基因表达的变化，多个基因参与果糖代谢的多个途径，以及缺乏一些参与果糖代谢的基因的表征，这些都使我们对果糖在神经能量学中的生理作用的理解变得复杂。最近的一项小脑神经代谢研究表明，浦肯野细胞中果糖代谢和果糖 1-磷酸途径特异基因 GLUT5 (glut5) 和酮己糖激酶 (khk) 的共表达表明这是特定神经元中的活跃途径？与此同时，对膳食果糖快速增加（尤其是儿童）的担忧，提高了人们对果糖在体内如何代谢以及高果糖饮食可能产生什么影响的认识。在这方面，建立细胞和分子研究以及果糖在大脑中发挥的重要和/或有害作用的生理学特征至关重要。本综述将讨论大脑中果糖代谢的状况，特别是小脑和不同途径的生理作用。
Under normal physiological conditions, the brain utilizes only a small number of carbon sources for energy. Recently, there is growing molecular and biochemical evidence that other carbon sources, including fructose, may play a role in neuroenergetics. Fructose is the number one commercial sweetener in Western civilization with large amounts of fructose being toxic, yet fructose metabolism remains relatively poorly characterized. Fructose is purportedly metabolizedviaeither of two pathways, the fructose-1-phosphate pathway and/or the fructose-6-phosphate pathway. Many early metabolic studies could not clearly discriminate which of these two pathways predominates, nor could they distinguish which cell types in various tissues are capable of fructose metabolism. In addition, the lack of good physiological models, the diet-induced changes in gene expression in many tissues, the involvement of multiple genes in multiple pathways involved in fructose metabolism, and the lack of characterization of some genes involved in fructose metabolism have complicated our understanding of the physiological role of fructose in neuro-energetics. A recent neuro-metabolism study of the cerebellum demonstrated fructose metabolism and co-expression of the genes specific for the fructose 1-phosphate pathway, GLUT5 (glut5) and ketohexokinase (khk), in Purkinje cells suggesting this as an active pathway in specific neurons? Meanwhile, concern over the rapid increase in dietary fructose, particularly among children, has increased awareness about how fructose is metabolizedin vivoand what effects a high fructose diet might have. In this regard, establishment of cellular and molecular studies and physiological characterization of the important and/or deleterious roles fructose plays in the brain is critical. This review will discuss the status of fructose metabolism in the brain with special reference to the cerebellum and the physiological roles of the different pathways.