Published online Jul 26, 2014. doi: 10.4330/wjc.v6.i7.610
Revised: February 21, 2014
Accepted: May 14, 2014
Published online: July 26, 2014
Processing time: 235 Days and 10.9 Hours
Post-myocardial infarction (MI), the left ventricle (LV) undergoes a series of events collectively referred to as remodeling. As a result, damaged myocardium is replaced with fibrotic tissue consequently leading to contractile dysfunction and ultimately heart failure. LV remodeling post-MI includes inflammatory, fibrotic, and neovascularization responses that involve regulated cell recruitment and function. Stem cells (SCs) have been transplanted post-MI for treatment of LV remodeling and shown to improve LV function by reduction in scar tissue formation in humans and animal models of MI. The promising results obtained from the application of SCs post-MI have sparked a massive effort to identify the optimal SC for regeneration of cardiomyocytes and the paradigm for clinical applications. Although SC transplantations are generally associated with new tissue formation, SCs also secrete cytokines, chemokines and growth factors that robustly regulate cell behavior in a paracrine fashion during the remodeling process. In this review, the different types of SCs used for cardiomyogenesis, markers of differentiation, paracrine factor secretion, and strategies for cell recruitment and delivery are addressed.
Core tip: Stem cell (SC)-based therapies hold promise to improve damaged myocardium repair and regeneration and thereby restore normal tissue function post-MI. In addition to the potential of SCs to regenerate myocardium, intrinsic properties of SCs such as their ability to home to areas of tissue damage make them an attractive tool for drug delivery. SCs, specifically mesenchymal stem cells, secrete multiple factors that can act in an autocrine and paracrine manner to regulate cell activation, recruitment, and survival during myocardium repair and regeneration.