Possible role of avian uncoupling protein in down-regulating mitochondrial superoxide production in skeletal muscle of fasted chickens
Possible role of avian uncoupling protein in down-regulating mitochondrial superoxide production in skeletal muscle of fasted chickens
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DOI：
10.1016/j.febslet.2006.07.070
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发表时间：
2006-09-04
期刊：
影响因子：
3.5
通讯作者：
Toyomizu, Masaaki
中科院分区：
文献类型：
--
作者：
Abe, Tomoki;Mujahid, Ahmad;Toyomizu, Masaaki
解偶联蛋白1（UCP 1）同源物（UCP 2，UCP 3，禽UCP）的确切生理作用知之甚少，其水平在禁食期间上调。骨骼肌中的UCP被认为在调节作为燃料底物的脂质和/或控制活性氧（ROS）的产生中起作用。本研究的目的是，使用骨骼肌禁食鸡，是检查在表达的基因编码禽UCP和相关的脂质通量的线粒体P-氧化途径的关键酶的变化。我们还阐明了avUCP含量的增加是否与线粒体ROS产生的改变有关。禁食24小时后，avUCP和CPT-I基因的转录水平分别增加了7.7倍和9.5倍，禁食48小时后略有下降，但仍分别比基线水平高出约5.0倍和7.7倍。相反，P-氧化途径的成员，LCAD和3 HADH，从12至48小时禁食逐渐上调。这表明，在禁食的初始阶段，脂肪酸的转移和氧化过程受到不同的上调。通过光泽精衍生的化学发光分析ROS的产生表明，FFA敏感部分的羧基糖苷上调ROS生产是更大的骨骼肌线粒体从24小时禁食鸡相比，这使我们假设，ROS的生产是潜在的下调UCP。积压的脂肪酸氧化的可能参与，观察鸡后，24它快，在跨膜梯度的游离非氧化脂肪酸进行了讨论。(c)2006年欧洲生物化学学会联合会。Elsevier B. V.出版，保留所有权利。
Little is known about the precise physiological roles of uncoupling protein 1 (UCP1) homologs (UCP2, UCP3, avian UCP) whose levels are up-regulated during fasting. UCPs in skeletal muscle are thought to play a role in the regulation of lipids as fuel substrates, and/or in controlling the production of reactive oxygen species (ROS). The aim of this investigation, using skeletal muscle from fasted chickens, was to examine alterations in the expression of genes encoding for avian UCP and key enzymes relevant to lipid flux across the mitochondrial P-oxidation pathway. We also clarified whether an increase in avUCP content could be associated with altered ROS production by mitochondria. Transcription levels of avUCP and CPT-I genes were increased 7.7- and 9.5-fold after a 24 h fast and slightly diminished but remained about 5.0- and 7.7-fold higher than baseline levels, respectively, after 48 h of fasting. In contrast, members of the P-oxidation pathway, LCAD and 3HADH, were gradually up-regulated from 12 to 48 h of fasting. This suggests that processes involved in the transfer and oxidation of fatty acids are up-regulated differently during the initial stage of fasting. Analysis of ROS production by lucigenin-derived chemiluminescence showed that,the FFA-sensitive portion of carboxyatractyloside-upregulated ROS production was greater in skeletal muscle mitochondria from 24 h-fasted chickens compared with control, which leads us to postulate that ROS production is potentially down-regulated by UCP. The possible involvement of a backlog of fatty acid for oxidation, observed in chickens after a 24 It fast, in a transmembrane gradient of free non-oxidized fatty acids is also discussed. (c) 2006 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.