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Fukushima A, Alrob OA, Zhang L, Wagg CS, Altamimi T, Rawat S, Rebeyka IM, Kantor PF, Lopaschuk GD. Acetylation and succinylation contribute to maturational alterations in energy metabolism in the newborn heart. Am J Physiol Heart Circ Physiol 311: H347-H363, 2016. First published June 3, 2016; doi:10.1152/ajpheart.00900.2015.-Dramatic maturational changes in cardiac energy metabolism occur in the newborn period, with a shift from glycolysis to fatty acid oxidation. Acetylation and succinylation of lysyl residues are novel posttranslational modifications involved in the control of cardiac energy metabolism. We investigated the impact of changes in protein acetylation/succinylation on the maturational changes in energy metabolism of 1-, 7-, and 21-day-old rabbit hearts. Cardiac fatty acid ␤-oxidation rates increased in 21-day vs. 1-and 7-day-old hearts, whereas glycolysis and glucose oxidation rates decreased in 21-day-old hearts. The fatty acid oxidation enzymes, long-chain acyl-CoA dehydrogenase (LCAD) and ␤-hydroxyacylCoA dehydrogenase (␤-HAD), were hyperacetylated with maturation, positively correlated with their activities and fatty acid ␤-oxidation rates. This alteration was associated with increased expression of the mitochondrial acetyltransferase, general control of amino acid synthesis 5 like 1 (GCN5L1), since silencing GCN5L1 mRNA in H9c2 cells significantly reduced acetylation and activity of LCAD and ␤-HAD. An increase in mitochondrial ATP production rates with maturation was associated with the decreased acetylation of peroxisome proliferator-activated receptor-␥ coactivator-1␣, a transcriptional regulator for mitochondrial biogenesis. In addition, hypoxiainducible factor-1␣, hexokinase, and phosphoglycerate mutase expression declined postbirth, whereas acetylation of these glycolytic enzymes increased. Phosphorylation rather than acetylation of pyruvate dehydrogenase (PDH) increased in 21-day-old hearts, accounting for the low glucose oxidation postbirth. A maturational increase was also observed in succinylation of PDH and LCAD. Collectively, our data are the first suggesting that acetylation and succinylation of the key metabolic enzymes in newborn hearts play a crucial role in cardiac energy metabolism with maturation.Listen to this article's corresponding podcast at http://ajpheart.podbean. com/e/acetylation-control-of-energy-metabolism-in-newborn-hearts/. myocardial fatty acid oxidation; lysine acetylation; lysine succinylation; newborn heart NEW & NOTEWORTHYThe present study is the first showing that alterations in acetylation and succinylation control of metabolic enzymes contribute to the dramatic shift in cardiac energy metabolism from glycolysis to fatty acid ␤-oxidation seen during maturation. Our results suggest that lysine acetylation enhances cardiac fatty acid ␤-oxidation and inhibits glycolysis during maturation.OVER 1% OF NEWBORNS ARE DIAGNOSED with congenital heart disease (CHD), with one-third of these needing surgery within the first months of life (36). Despite the major advance...

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The heat transfer assessments in a Sisko nanofluid flow over a stretching surface in a Darcy-Forchheimer porous medium with heat generation and thermal radiation are studied. The numerical analysis technique is used to assess the governing nonlinear equations of the model. The influence of Forchheimer number, porosity, heat generation, radiation, and material parameters is examined. The outlines of Nusselt number and skin friction coefficient corresponding to pertinent parameters are revealed. The comparison of Nusselt number outlines of working fluid and Newtonian fluid is depicted. From the analysis, it has been examined that with the increase in Forchheimer number and material parameter values, heat transfer function decreases, whereas heat transfer characteristics of Sisko nanofluid increase with heat generation and material parameters. Moreover, working fluid velocity outlines depreciate when there is an increase in porosity parameter for both shear-thinning and shearthickening. The comparison of this study with previous research has been conducted.

Purpose The purpose of this paper is to explore the flow of Cu-water and Ag-water nanofluids past a vertical Riga plate. The plate is infinite in height and has zero normal wall flux through its surface. Influence of thermal radiation, slip, suction and chemical reaction on the flow characteristics are reported. Design/methodology/approach Non-dimensional forms of the flow governing equations are obtained by means of a set of similarity transformations. Numerical solution is obtained with the help of fourth-fifth-order Runge–Kutta–Fehlberg method with shooting procedure. Comparison of solution profiles of Cu-water and Ag-water nanofluids are presented graphically and with the help of tables. Influence of pertinent parameters on skin friction and heat transfer rate is also reported. Findings Results reveal that the skin friction coefficient is more prominent in the case of Ag-water nanofluid for an increase in thermal radiation and volume fraction. The role of suction and slip is to increase velocity but decrease the temperature in both nanofluids. Temperature and velocity of both nanofluids increase as volume fraction and thermal radiation values are augmented. Heat transport increases with thermal radiation. Region near the plate experiences rise in nanoparticle concentration with an increase in chemical reaction parameter. Originality/value A complete investigation of the modeled problem is addressed and the results of this paper are original.