Secretome from resident cardiac stromal cells stimulates proliferation, cardiomyogenesis and angiogenesis of progenitor cells

In the heart, tissue-derived signals play a central role on recruiting/activating stemcell sources to induce cardiac lineage specification for maintenance of tissue homeostasis and repair. Cardiac resident stromal cells (CRSCs) may play a pivotal role in cardiac repair throughout their secretome. Here, we performed the characterization of CRSCs and their secretome by analyzing the composition of their culture-derived extracellular matrix (ECM) and conditioned medium (CM) and by investigating their potential effect on adipose-derived stem cell (ADSC) and progenitor cell behavior. We confirmed that CRSCs are a heterogeneous cell population whose secretome is composed by proteins related to cellular growth, immune response and cardiovascular development and function. We also observed that CRSC secretomewas unable to change the behavior of ADSCs, except for proliferation. Additionally, CMfromCRSCs demonstrated the potential to drive proliferation and cardiac differentiation of H9c2 cells and also the ability to induce angiogenesis in vitro. Our data suggest that the CRSCs can be a source of important modulating signals for cardiac progenitor cell recruitment/activation. (C) 2016 Elsevier Ireland Ltd. All rights reserved.