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Franko 2012 J Mol Med

From Bioblast
Publications in the MiPMap
Franko A, von Kleist-Retzow JC, Böse M, Sanchez-Lasheras C, Brodesser S, Krut O, Kunz WS, Wiedermann D, Höhn M, Stöhr O, Moll L, Freude S, Krone W, Schubert M, Wiesner RJ (2012) Complete failure of insulin-transmitted signaling, but not obesity-induced insulin resistance, impairs respiratory chain function in muscle. J Mol Med 90:1145-60.

» PMID: 22411022

Franko A, von Kleist-Retzow JC, Boese M, Sanchez-Lasheras C, Brodesser S, Krut O, Kunz WS, Wiedermann D, Hoehn M, Stoehr O, Moll L, Freude S, Krone W, Schubert M, Wiesner RJ (2012) J Mol Med

Abstract: The role of mitochondrial dysfunction in the development of insulin resistance and type 2 diabetes remains controversial. In order to specifically define the relationship between insulin receptor (InsR) signaling, insulin resistance, hyperglycemia, hyperlipidemia and mitochondrial function, we analyzed mitochondrial performance of insulin-sensitive, slow-oxidative muscle in four different mouse models. In obese but normoglycemic ob/ob mice as well as in obese but diabetic mice under high-fat diet, mitochondrial performance remained unchanged even though intramyocellular diacylglycerols (DAGs), triacylglycerols (TAGs), and ceramides accumulated. In contrast, in muscle-specific InsR knockout (MIRKO) and streptozotocin (STZ)-treated hypoinsulinemic, hyperglycemic mice, levels of mitochondrial respiratory chain complexes and mitochondrial function were markedly reduced. In STZ, but not in MIRKO mice, this was caused by reduced transcription of mitochondrial genes mediated via decreased PGC-1α expression. We conclude that mitochondrial dysfunction is not causally involved in the pathogenesis of obesity-associated insulin resistance under normoglycemic conditions. However, obesity-associated type 2 diabetes and accumulation of DAGs or TAGs is not associated with impaired mitochondrial function. In contrast, chronic hypoinsulinemia and hyperglycemia as seen in STZ-treated mice as well as InsR deficiency in muscle of MIRKO mice lead to mitochondrial dysfunction. We postulate that decreased mitochondrial mass and/or performance in skeletal muscle of non-diabetic, obese or type 2 diabetic, obese patients observed in clinical studies must be explained by genetic predisposition, physical inactivity, or other still unknown factors. Keywords: Type 2 diabetes mellitus, Mitochondrial biogenesis, Mitochondrial gene expression, Insulin receptor, Muscle metabolism, in vivo NMR spectroscopy, Lipid metabolism, Ceramides, ob/ob mice, Muscle-specific InsR knockout (MIRKO) mice

O2k-Network Lab: DE Cologne Larsson NG, DE Cologne Wiesner RJ

Labels: MiParea: Genetic knockout;overexpression  Pathology: Diabetes 

Organism: Mouse  Tissue;cell: Skeletal muscle 

HRR: Oxygraph-2k