Objective:
Stem cell therapy to repair cardiac damage, caused by the pathological remodeling that occurs in cardiovascular disease, represents a cutting edge therapeutic option toward preventing and treating heart failure. There is a paucity of information on how the phenotypes of stem cells are altered in the “hostile” environment of pathologically remodeled hearts. The objective of this study was to (a) determine the phenotypes of cardiac stem cells cultured on failing versus normal human heart tissue, and (b) to characterize pathology of failing human heart samples.
Methods:
We isolated the extracellular matrix (ECM) from end-stage failing human hearts (compared to control human hearts) and used the isolated ECM to coat tissue culture plates. The ECM represents the scaffold of the heart in which stem cells will integrate, proliferate, and differentiate. We then cultured induced pluripotent stem cell-derived cardiac progenitor cells on the cardiac-ECM plates and analyzed their phenotypes (morphology, differentiation into cardiomyocytes, and gene expression). We also performed analysis of the failing cardiac tissue itself to determine the extent of fibrosis and expression of various ECM and matricellular proteins.
Results:
Cells cultured on failing heart ECM showed important differences compared to those on control heart ECM, including reduced cell-matrix adhesion and altered responses to beta-adrenergic stimulation. The failing heart shows increased fibrosis and differential expression of specific ECM and matricellular proteins.
Significance:
We will use these data to determine how best to direct cardiac stem cells used for tissue generation in severely damaged hearts toward differentiation into functioning cardiomyocytes.
Cardiac Stem Cells in the Failing Human Heart
