Galactose enhances oxidative metabolism and reveals mitochondrial dysfunction in human primary muscle cells.
Galactose enhances oxidative metabolism and reveals mitochondrial dysfunction in human primary muscle cells.
复制标题
DOI：
10.1371/journal.pone.0028536
复制
发表时间：
2011
期刊：
影响因子：
3.7
通讯作者：
Harper ME
中科院分区：
文献类型：
--
作者：
Aguer C;Gambarotta D;Mailloux RJ;Moffat C;Dent R;McPherson R;Harper ME
人原代肌管在高糖培养基中培养时高度糖酵解，使得难以研究线粒体功能障碍。已知半乳糖可增强线粒体代谢，并且可成为研究人初级肌管中线粒体功能障碍的极好模型。本研究的目的是1）表征半乳糖中分化的健康人成肌细胞对氧化代谢的影响和2）确定半乳糖是否可以精确定位糖尿病后肌管中的线粒体功能障碍。在不同来源/浓度的碳水化合物中分化的健康肌管中测定了耗氧率（OCR）、乳酸水平、线粒体含量、柠檬酸合酶和细胞色素C氧化酶活性以及AMPK磷酸化：25 mM葡萄糖（高葡萄糖（HG））、5 mM葡萄糖（低葡萄糖（LG））或10 mM半乳糖（GAL）。碳水化合物对OCR的影响也在来自糖尿病后患者和匹配的肥胖非糖尿病受试者的肌管中确定。与LG或HG肌管相比，GAL肌管中OCR显著增加，而无氧糖酵解显著降低。GAL肌管中OCR的增加与细胞色素C氧化酶活性和表达的增加以及AMPK磷酸化的增加有关。糖尿病后肌管的OCR在LG或HG中分化时与肥胖非糖尿病肌管的OCR没有差异。然而，尽管GAL增加了肥胖非糖尿病肌管中的OCR，但它不影响糖尿病后肌管中的OCR，导致组间OCR的显著差异。在GAL分化的糖尿病后肌管中OCR增加的缺乏与未改变的细胞色素C氧化酶活性水平或AMPK磷酸化有关。我们的研究结果表明，在GAL分化的人原代成肌细胞增强有氧代谢。由于这种细胞培养模型引起了糖尿病后患者细胞的异常反应，因此可能有助于进一步研究线粒体功能障碍的分子机制。
Human primary myotubes are highly glycolytic when cultured in high glucose medium rendering it difficult to study mitochondrial dysfunction. Galactose is known to enhance mitochondrial metabolism and could be an excellent model to study mitochondrial dysfunction in human primary myotubes. The aim of the present study was to 1) characterize the effect of differentiating healthy human myoblasts in galactose on oxidative metabolism and 2) determine whether galactose can pinpoint a mitochondrial malfunction in post-diabetic myotubes. Oxygen consumption rate (OCR), lactate levels, mitochondrial content, citrate synthase and cytochrome C oxidase activities, and AMPK phosphorylation were determined in healthy myotubes differentiated in different sources/concentrations of carbohydrates: 25 mM glucose (high glucose (HG)), 5 mM glucose (low glucose (LG)) or 10 mM galactose (GAL). Effect of carbohydrates on OCR was also determined in myotubes derived from post-diabetic patients and matched obese non-diabetic subjects. OCR was significantly increased whereas anaerobic glycolysis was significantly decreased in GAL myotubes compared to LG or HG myotubes. This increased OCR in GAL myotubes occurred in conjunction with increased cytochrome C oxidase activity and expression, as well as increased AMPK phosphorylation. OCR of post-diabetic myotubes was not different than that of obese non-diabetic myotubes when differentiated in LG or HG. However, whereas GAL increased OCR in obese non-diabetic myotubes, it did not affect OCR in post-diabetic myotubes, leading to a significant difference in OCR between groups. The lack of an increase in OCR in post-diabetic myotubes differentiated in GAL was in relation with unaltered cytochrome C oxidase activity levels or AMPK phosphorylation. Our results indicate that differentiating human primary myoblasts in GAL enhances aerobic metabolism. Because this cell culture model elicited an abnormal response in cells from post-diabetic patients, it may be useful in further studies of the molecular mechanisms of mitochondrial dysfunction.
登录
查看更多内容
影响因子：
7.7
作者：
Gaster, M;Rustan, AC;Beck-Nielsen, H
通讯作者：
Beck-Nielsen, H
影响因子：
7.7
作者：
Foretz, M;Ancellin, N;Viollet, B
通讯作者：
Viollet, B
DOI：
10.1073/pnas.0705070104
发表时间：
2007-07-17
影响因子：
11.1
作者：
Jaeger, Sibylle;Handschin, Christoph;Spiegelman, Bruce M.
通讯作者：
Spiegelman, Bruce M.
影响因子：
7.7
作者：
Koistinen, HA;Galuska, D;Wallberg-Henriksson, H
通讯作者：
Wallberg-Henriksson, H
影响因子：
11.8
作者：
Fulco, Marcella;Cen, Yana;Sartorelli, Vittorio
通讯作者：
Sartorelli, Vittorio