Kappler 2019 Am J Physiol Endocrinol Metab
|Kappler L, Hoene M, Hu C, von Toerne C, Li J, Bleher D, Hoffmann C, Böhm A, Kollipara L, Zischka H, Königsrainer A, Häring HU, Peter A, Xu G, Sickmann A, Hauck SM, Weigert C, Lehmann R (2019) Linking bioenergetic function of mitochondria to tissue-specific molecular fingerprints. Am J Physiol Endocrinol Metab 317:E374-E387.|
Abstract: Mitochondria are dynamic organelles with diverse functions in tissues such as liver and skeletal muscle. To unravel the mitochondrial contribution to tissue-specific physiology, we performed a systematic comparison of the mitochondrial proteome and lipidome of mice and assessed the consequences hereof for respiration. Liver and skeletal muscle mitochondrial protein composition was studied by data-independent UHPLC-MS/MS-proteomics, lipid profiles were compared by UHPLC-MS/MS lipidomics. Mitochondrial function was investigated by high-resolution respirometry in samples from mice and humans. Enzymes of pyruvate oxidation as well as several subunits of complex I, III, and ATP synthase were more abundant in muscle mitochondria. Muscle mitochondria were enriched in cardiolipins associated with higher oxidative phosphorylation capacity and flexibility, in particular CL(18:2)4 and 22:6-containing cardiolipins. In contrast, protein equipment of liver mitochondria indicated a shuttling of complex I substrates towards gluconeogenesis and ketogenesis and a higher preference for electron transfer via the flavoprotein quinone oxidoreductase pathway. Concordantly, muscle and liver mitochondria showed distinct respiratory substrate preferences. Muscle respired significantly more on the complex I substrates pyruvate and glutamate, while in liver maximal respiration was supported by complex II substrate succinate. This was a consistent finding in mouse liver and skeletal muscle mitochondria and human samples. Muscle mitochondria are tailored to produce ATP with a high capacity for complex I‑linked substrates. Liver mitochondria are more connected to biosynthetic pathways, preferring fatty acids and succinate for oxidation. The physiologic diversity of mitochondria may help to understand tissue-specific disease pathologies and to develop therapies targeting mitochondrial function.
Labels: MiParea: Respiration, Comparative MiP;environmental MiP
Organism: Human, Mouse Tissue;cell: Skeletal muscle, Liver Preparation: Permeabilized tissue, Isolated mitochondria Enzyme: Complex I, Complex II;succinate dehydrogenase, Complex III, Complex IV;cytochrome c oxidase, Complex V;ATP synthase
Coupling state: LEAK, OXPHOS, ET Pathway: F, N, S, NS HRR: Oxygraph-2k