title: Triiodothyronine prevents cardiac ischemia/reperfusion mitochondrial impairment and cell loss by regulating miR30a/p53 axis.
abstract: Mitochondrial dysfunctions critically affect cardiomyocyte survival during ischemia/reperfusion (I/R) injury. In this scenario p53 activates multiple signaling pathways that impair cardiac mitochondria and promote cell death. p53 is a validated target of miR-30 whose levels fall under ischemic conditions. Although triiodothyronine (T3) rescues post-ischemic mitochondrial activity and cell viability, no data are available on its role in the modulation of p53 signaling in I/R. Here we test the hypothesis that early T3 supplementation in rats inhibits the post I/R activation of p53 pro-death cascade through the maintenance of miRNA 30a expression. In our model, T3 infusion improves the recovery of post-ischemic cardiac performance. At the molecular level, the beneficial effect of T3 is associated with restored levels of miR-30a expression in the area at risk (AAR) that correspond to p53 mRNA downregulation. The concomitant decrease in p53 protein content reduces Bax expression and limits mitochondrial membrane depolarization resulting in preserved mitochondrial function and decreased apoptosis and necrosis extent in the AAR. Also in primary cardiomyocyte culture of neonatal rats, T3 prevents both miR-30a downregulation and p53 raise induced by hypoxia. The regulatory effect of T3 is greatly suppressed by miR-30a knockdown. Overall these data suggest a new mechanism of T3-mediated cardioprotection that is targeted to mitochondria and acts, at least in part, through the regulation of miR-30a/p53 axis.
authors.affiliation: Consiglio Nazionale delle Ricerche (CNR) Institute of Clinical Physiology (F.F., C.K., G.N., L.M., G.I., L.P), Via G. Moruzzi 1, Pisa, Italy; Department of Pathology (R.Z., G.I.), University of Pisa, 56127 Pisa, Italy; Scuola Superiore Sant'Anna (M.M., G.I.), Piazza Martiri della Libertà 33, 56127 Pisa, Italy; and CNR/Tuscany Region G Monasterio Foundation (G.I.), Via G. Moruzzi 1, 56124 Pisa, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Forini
authors.forename: Claudia
authors.initials: C
authors.lastname: Kusmic
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Nicolini
authors.forename: Laura
authors.initials: L
authors.lastname: Mariani
authors.forename: Riccardo
authors.initials: R
authors.lastname: Zucchi
authors.forename: Marco
authors.initials: M
authors.lastname: Matteucci
authors.forename: Giorgio
authors.initials: G
authors.lastname: Iervasi
authors.forename: Letizia
authors.initials: L
authors.lastname: Pitto
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D008297:Male; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D008929:Mitochondria, Heart / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D015428:Myocardial Reperfusion Injury / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D013963:Thyroid Hormones / Q000378:metabolism; D014284:Triiodothyronine / Q000494:pharmacology*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics* / Q000378:metabolism
chemical_list: C556157:MIRN30 microRNA, rat; D035683:MicroRNAs; D013963:Thyroid Hormones; D016159:Tumor Suppressor Protein p53; D014284:Triiodothyronine