Stride 2012 Front Physiol
| Stride N, Larsen S, Treebak JT, Hansen CN, Hey-Mogensen M, Speerschneider T, Jensen TE, Jeppesen J, Wojtaszewski JF, Richter EA, KΓΈber L, Dela F (2012) 5'-AMP activated protein kinase is involved in the regulation of myocardial Ξ²-oxidative capacity in mice. Front Physiol 3:33. |
Stride N, Larsen S, Treebak JT, Hansen CN, Hey-Mogensen M, Speerschneider T, Jensen TE, Jeppesen J, Wojtaszewski JF, Richter EA, Koeber L, Dela F (2012) Front Physiol
Abstract: 5'-adenosine monophosphate-activated protein kinase (AMPK) is considered central in regulation of energy status and substrate utilization within cells. In heart failure the energetic state is compromised and substrate metabolism is altered. We hypothesized that this could be linked to changes in AMPK activity and we therefore investigated mitochondrial oxidative phosphorylation capacity from the oxidation of long- and medium-chain fatty acids (LCFA and MCFA) in cardiomyocytes from young and old mice expressing a dominant negative AMPKΞ±2 (AMPKΞ±2-KD) construct and their wildtype (WT) littermates. We found a 35-45% (Pβ<β0.05) lower mitochondrial capacity for oxidizing MCFA in AMPKΞ±2-KD of both age-groups, compared to WT. This coincided with marked decreases in protein expression (19/29%, Pβ<β0.05) and activity (14/21%, Pβ<β0.05) of 3-hydroxyacyl-CoA-dehydrogenase (HAD), in young and old AMPKΞ±2-KD mice, respectively, compared to WT. Maximal LCFA oxidation capacity was similar in AMPKΞ±2-KD and WT mice independently of age implying that LCFA-transport into the mitochondria was unaffected by loss of AMPK activity or progressing age. Expression of regulatory proteins of glycolysis and glycogen breakdown showed equivocal effects of age and genotype. These results illustrate that AMPK is necessary for normal mitochondrial function in the heart and that decreased AMPK activity may lead to an altered energetic state as a consequence of reduced capacity to oxidize MCFA. We did not identify any clear aging effects on mitochondrial function. β’ Keywords: dominant negative AMPKΞ±2 (AMPKΞ±2-KD), 5'-adenosine monophosphate-activated protein kinase (AMPK)
β’ O2k-Network Lab: DK Copenhagen Dela F
Labels: MiParea: Respiration, Genetic knockout;overexpression
Pathology: Aging;senescence, Other
Organism: Mouse Tissue;cell: Heart Preparation: Permeabilized tissue
Coupling state: OXPHOS
Pathway: F
HRR: Oxygraph-2k
