Abstract 450: Unveiling Human Cardiac Stem Cells Role in Myocardial Ischemia-reperfusion Injury

• Published in: Circulation research 2016-07, Vol.119 (suppl_1)
• Main Authors: Sebastião, Maria J, Serra, Margarida, Pereira, Rute, Brito, Catarina, Palacios, Itziar, Gomes-Alves, Patrícia, Alves, Paula M
• Format: Article
• Language: English
• ISSN: 0009-7330; 1524-4571
• DOI: 10.1161/res.119.suppl_1.450

Abstract only After an Acute Myocardial Infarction (AMI), Ischemia-Reperfusion (I/R) injury is responsible for a critical decrease in the number of viable cardiomyocytes (hCMs). Human adult myocardium harbors a population of endogenous cardiac stem cells (hCSCs) that is activated upon I/R injury, contributing to myocardial repair through the establishment of an auto/paracrine molecular crosstalk between hCSCs and hCMs in stress. Our work aims at setting up the first in vitro human I/R injury model in order to decipher the role of hCSCs and correspondent cross talk between hCSCs and hCMs upon AMI using proteomic tools. Human CSCs, hCMs cultures and co-cultures were established using human donor derived CSCs (c-kit + , CD45 - ) and hCMs derived from human induced pluripotent stem cells at different maturation stages (hiPSC-CMs). Ischemia was mimicked by substituting growth media by Ischemia Mimetic Solution (including nutrient depletion, lactate accumulation, acidosis and hyperosmosis) and placing the cells at 0% O 2 for 5 hours. In the reperfusion step, cells were placed back in their physiological culture conditions (3% O 2 ). The effect of I/R injury on growth factor secretion, cells’ viability, as well as on hCSC proliferation was accessed in both mono- and co-culture systems. In addition, hCSCs total proteome analysis was performed at different timepoints (before injury, after ischemia and after 1h and 16h of reoxygenation) by LC-MS. Important features of I/R injury were successfully captured in our model, namely hCSC proliferation activation upon insult, the increase in HGF secretion during the first hour after reoxygenation, and the protective role of hCSCs on hiPSC-CMs. The maturation stage of hiPSC-CM showed to be of high relevance in the response to injury. More than 2000 proteins were identified in hCSCs per experimental time point; proteins associated with mitochondrial dysfunction and oxidative stress response were identified in hCSCs exposed to injury. This system will allow further understanding on the molecular landscape of the myocardium during AMI, namely regarding hCSC regenerative response and hCM survival. The knowledge gained in this work will potentiate the development of novel therapies for myocardium regeneration.