Comprehensive Metabolic Profiling of Age-Related Mitochondrial Dysfunction in the High-Fat-Fed ob/ob Mouse Heart

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• 作者：Xinzhu Wang ; James A. West ; Andrew J. Murray ; Julian L. Griffin
• 刊名：Journal of Proteome Research
• 出版年：2015
• 出版时间：July 2, 2015
• 年：2015
• 卷：14
• 期：7
• 页码：2849-2862
• 全文大小：700K
• ISSN：1535-3907

文摘

The ectopic deposition of fat is thought to lead to lipotoxicity and has been associated with mitochondrial dysfunction and diabetic cardiomyopathy. We have measured mitochondrial respiratory capacities in the hearts of ob/ob and wild-type mice on either a regular chow (RCD) or high-fat (HFD) diet across four age groups to investigate the impact of diet and age on mitochondrial function alongside a comprehensive strategy for metabolic profiling of the tissue. Myocardial mitochondrial dysfunction was only evident in ob/ob mice on RCD at 14 months, but it was detectable at 3 months on the HFD. Liquid chromatography鈥搈ass spectrometry (LC鈥揗S) was used to study the profiles of acylcarnitines and the accumulation of triglycerides, but neither class of lipid was associated with mitochondrial dysfunction. However, a targeted LC鈥揗S/MS analysis of markers of oxidative stress demonstrated increases in GSSG/GSH and 8-oxoguanine, in addition to the accumulation of diacylglycerols, which are lipid species linked to lipotoxicity. Our results demonstrate that myocardial mitochondria in ob/ob mice on RCD maintained a similar respiratory capacity to that of wild type until a late stage in aging. However, on a HFD, unlike wild-type mice, ob/ob mice failed to increase mitochondrial respiration, which may be associated with a complex I defect following increased oxidative damage.