Age-dependent functional crosstalk between cardiac fibroblasts and cardiomyocytes in a 3D engineered cardiac tissue

Abstract

Complex heterocellular interactions between cardiomyocytes and fibroblasts in the heart involve their bidirectional signaling via cell-cell contacts, paracrine factors, and extracellular matrix (ECM). These interactions vary with heart development and pathology leading to changes in cardiac structure and function. Whether cardiac fibroblasts of different ages interact differentially with cardiomyocytes to distinctly impact their function remains unknown. Here, we explored the direct structural and functional effects of fetal and adult cardiac fibroblasts on cardiomyocytes using a tissue-engineered 3D co-culture system. We show that the age of cardiac fibroblasts is a strong determinant of the structure, function, and molecular properties of co-cultured tissues. In particular, in vitro expanded adult, but not fetal, cardiac fibroblasts significantly deteriorated electrical and mechanical function of the co-cultured cardiomyocytes, as evidenced by slower action potential conduction, prolonged action potential duration, weaker contractions, higher tissue stiffness, and reduced calcium transient amplitude. This functional deficit was associated with structural and molecular signatures of pathological remodeling including fibroblast proliferation, interstitial collagen deposition, and upregulation of pro-fibrotic markers. Our studies imply critical roles of the age of supporting cells in engineering functional cardiac tissues and provide a new physiologically relevant in vitro platform to investigate influence of heterocellular interactions on cardiomyocyte function, development, and disease.

3D Co-culture of hiPSC-Derived Cardiomyocytes With Cardiac Fibroblasts Improves Tissue-Like Features of Cardiac Spheroids

“…For preparing co-culture cardiac spheroids, CF and hiPSC-CM were detached from 2D culture bottles, or directly thawed from cryopreserved storage vessels in case of iCell 2 cardiomyocytes and diluted with plating medium so that a ratio hiPSC-CM:CF of 4:1 resulted. Fibroblasts selected for this study were from fetal origin and should not induce a pro-fibrotic effect in 3D co-culture (Li et al, 2017). For each spheroid 40 microliter of medium containing 5,000 cells were used for self-assembly using the GravityPlus TM hanging-drop system (InSphero, Switzerland).…”

Osteopontin: A Promising Therapeutic Target in Cardiac Fibrosis

“…For the heart to continue to function in a state of equilibrium, very intricate crosstalk between the different types of cells residing in the heart, as well as their interaction with the ECM, is orchestrated [33]. While cardiomyocytes constitute approximately two thirds of the myocardial tissue volume, cardiac fibroblasts actually have the highest cell population in the myocardium (accounting for approximately two thirds of the overall cells) [9].…”

Myocardium Metabolism in Physiological and Pathophysiological States: Implications of Epicardial Adipose Tissue and Potential Therapeutic Targets

“…The mitochondria lose capacity to metabolize fatty acids or glucose, and the oxygen left produces reactive oxygen species [95]. They might trigger apoptotic signaling on cardiomyocytes and myocardium remodeling and might modify the intercell communication and metabolism [96]. The deficiency of oxidative metabolism in myocardium and the reduction of catecholamines, fasting, or exercise-induced lipolytic response [97,98] on adipose tissue contributes to the increment of epicardial fat [99].…”