scholarly journals Hypoxia Inhibits the Peroxisome Proliferator-activated Receptor α/ Retinoid X Receptor Gene Regulatory Pathway in Cardiac Myocytes

2001 ◽  
Vol 276 (29) ◽  
pp. 27605-27612 ◽  
Author(s):  
Janice M. Huss ◽  
Fiona H. Levy ◽  
Daniel P. Kelly
Keyword(s):  
Cardiac Myocytes ◽  
Receptor Gene ◽  
Retinoid X Receptor ◽  
Peroxisome Proliferator ◽  
Regulatory Pathway ◽  
Peroxisome Proliferator Activated Receptor ◽  
Gene Regulatory

scholarly journals Peroxisome proliferator-activated receptor α-retinoid X receptor agonists induce beta-cell protection against palmitate toxicity

FEBS Journal ◽  
2007 ◽  
Vol 274 (23) ◽  
pp. 6094-6105 ◽  
Author(s):  
Karine Hellemans ◽  
Karen Kerckhofs ◽  
Jean-Claude Hannaert ◽  
Geert Martens ◽  
Paul Van Veldhoven ◽  
...  
Keyword(s):  
Beta Cell ◽  
Retinoid X Receptor ◽  
Peroxisome Proliferator ◽  
Cell Protection ◽  
Peroxisome Proliferator Activated Receptor ◽  
Receptor Agonists ◽  
Beta Cell Protection

Abstract 331: Recovery of Mitochondrial Bioenergetics after Hypoxia via Regulating Pyruvate Dehydrogenase Kinase and Adenosine Monophosphate-activated Kinase

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Jessica M Toli ◽  
Minzhen He ◽  
Carolyn Suzuki ◽  
Maha Abdellatif
Keyword(s):  
Fatty Acid ◽  
Oxidative Phosphorylation ◽  
Cardiac Myocytes ◽  
Pyruvate Dehydrogenase ◽  
Pyruvate Dehydrogenase Kinase ◽  
Neonatal Rat ◽  
Acid Oxidation ◽  
Peroxisome Proliferator ◽  
Mitochondrial Bioenergetics ◽  
Peroxisome Proliferator Activated Receptor

Mitochondrial quality control is critical for the survival of cardiac myocytes during stress. The purpose of this study was to examine the effect of metabolic substrates and regulators of metabolism on mitochondrial bioenergetics, as an indicator of mitochondrial quality, and how these factors might influence the recovery of the cell’s bioenergetics after hypoxia/ischemia. By monitoring oxygen consumption rates (OCR), in real-time, in live neonatal rat myocytes and human cardiac myocyte-differentiated induced pluripotent stem cells, we found that both cell types can maintain basal OCR efficiently with any metabolic substrate; however, the neonatal cells require both glucose and fatty acid, while the human adult cells require fatty acid only, for mounting maximum reserve respiratory capacity (RRC). Our data also show that subjecting cardiac myocytes to hypoxia results in a reduction of the cells’ basal OCR and oxidative phosphorylation, and exhausts the RRC, which is accompanied by an increase in pyruvate dehydrogenase kinase (Pdk) 1 and 4. Except for normalization of Pdk1 levels, there was little or no recovery of these parameters after reoxygenation. We, thus, hypothesized, that inhibition of Pdks may help recovery of the cell’s bioenergetics. Indeed, our results show that by inhibiting Pdks with dichloroacetate (DCA) before or after hypoxia, the cells’ bioenergetics, including OCR, oxidative phosphorylation, and RRC in neonatal myocytes, and RRC in the human myocytes fully recover within 24 h. On the other hand, activating AMP-activated kinase (AMPK) resulted in delayed (96 h) improvement of the cells’ RRC that was accompanied by an increase in peroxisome proliferator-activated receptor gamma, coactivator 1α (3.5x), peroxisome proliferator-activated receptor-α (2x), and mitochondrial number (2x). These results led us to conclude that compromised mitochondrial quality can be rescued through mechanisms that regulate glucose or fatty acid oxidation by either inhibiting Pdks or activating AMPK, respectively, in rodent and human myocytes.

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