Upregulation of genes involved in cardiac metabolism enhances myocardial resistance to ischemia/reperfusion in the rat heart
| Autor: | František Kolář, P. Mandíková, Táňa Ravingerová, Nemčeková M, Antigone Lazou, Adriana Adameova, Eleftheria Galatou, A. Chytilová, Eleftheria Barlaka, V. Ledvényiová, S Carnicka |
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| Rok vydání: | 2013 |
| Předmět: |
Male
medicine.medical_specialty Physiology Ischemia Peroxisome proliferator-activated receptor Myocardial Reperfusion Injury Biology Downregulation and upregulation Internal medicine medicine Animals PPAR alpha Rats Wistar PI3K/AKT/mTOR pathway Cardioprotection chemistry.chemical_classification Myocardium Glucose transporter General Medicine Recovery of Function medicine.disease Pyruvate dehydrogenase complex Rats Up-Regulation Endocrinology Pyrimidines Treatment Outcome chemistry Carnitine palmitoyltransferase I |
| Zdroj: | Scopus-Elsevier |
| ISSN: | 1802-9973 |
| Popis: | UNLABELLED Genes encoding enzymes involved in fatty acids (FA) and glucose oxidation are transcriptionally regulated by peroxisome proliferator-activated receptors (PPAR), members of the nuclear receptor superfamily. Under conditions associated with O(2) deficiency, PPAR-alpha modulates substrate switch (between FA and glucose) aimed at the adequate energy production to maintain basic cardiac function. Both, positive and negative effects of PPAR-alpha activation on myocardial ischemia/reperfusion (I/R) injury have been reported. Moreover, the role of PPAR-mediated metabolic shifts in cardioprotective mechanisms of preconditioning (PC) is relatively less investigated. We explored the effects of PPAR-alpha upregulation mimicking a delayed "second window" of PC on I/R injury in the rat heart and potential downstream mechanisms involved. Pretreatment of rats with PPAR-alpha agonist WY-14643 (WY, 1 mg/kg, i.p.) 24 h prior to I/R reduced post-ischemic stunning, arrhythmias and the extent of lethal injury (infarct size) and apoptosis (caspase-3 expression) in isolated hearts exposed to 30-min global ischemia and 2-h reperfusion. Protection was associated with remarkably increased expression of PPAR-alpha target genes promoting FA utilization (medium-chain acyl-CoA dehydrogenase, pyruvate dehydrogenase kinase-4 and carnitine palmitoyltransferase I) and reduced expression of glucose transporter GLUT-4 responsible for glucose transport and metabolism. In addition, enhanced Akt phosphorylation and protein levels of eNOS, in conjunction with blunting of cardioprotection by NOS inhibitor L-NAME, were observed in the WY-treated hearts. CONCLUSIONS upregulation of PPAR-alpha target metabolic genes involved in FA oxidation may underlie a delayed phase PC-like protection in the rat heart. Potential non-genomic effects of PPAR-alpha-mediated cardioprotection may involve activation of prosurvival PI3K/Akt pathway and its downstream targets such as eNOS and subsequently reduced apoptosis. |
| Databáze: | OpenAIRE |
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