Global Intracoronary Infusion of Allogeneic Cardiosphere-Derived Cells Improves Ventricular Function and Stimulates Endogenous Myocyte Regeneration throughout the Heart in Swine with Hibernating Myocardium

Abstract

BackgroundCardiosphere-derived cells (CDCs) improve ventricular function and reduce fibrotic volume when administered via an infarct-related artery using the “stop-flow” technique. Unfortunately, myocyte loss and dysfunction occur globally in many patients with ischemic and non-ischemic cardiomyopathy, necessitating an approach to distribute CDCs throughout the entire heart. We therefore determined whether global intracoronary infusion of CDCs under continuous flow improves contractile function and stimulates new myocyte formation.Methods and ResultsSwine with hibernating myocardium from a chronic LAD occlusion were studied 3-months after instrumentation (n = 25). CDCs isolated from myocardial biopsies were infused into each major coronary artery (∼33×106 icCDCs). Global icCDC infusion was safe and while ∼3% of injected CDCs were retained, they did not affect ventricular function or myocyte proliferation in normal animals. In contrast, four-weeks after icCDCs were administered to animals with hibernating myocardium, %LADWT increased from 23±6 to 51±5% (p<0.01). In diseased hearts, myocyte proliferation (phospho-histone-H3) increased in hibernating and remote regions with a concomitant increase in myocyte nuclear density. These effects were accompanied by reductions in myocyte diameter consistent with new myocyte formation. Only rare myocytes arose from sex-mismatched donor CDCs.ConclusionsGlobal icCDC infusion under continuous flow is feasible and improves contractile function, regresses myocyte cellular hypertrophy and increases myocyte proliferation in diseased but not normal hearts. New myocytes arising via differentiation of injected cells are rare, implicating stimulation of endogenous myocyte regeneration as the primary mechanism of repair.

Inhibiting Extracellular Vesicle Release from Human Cardiosphere Derived Cells with Lentiviral Knockdown of nSMase2 Differentially Effects Proliferation and Apoptosis in Cardiomyocytes, Fibroblasts and Endothelial Cells In Vitro

“…Cardiosphere-derived cells were grown as previously described from each patient [2]. In brief, heart biopsies were minced into small fragments, washed, and briefly digested with type IV collagenase for 60 minutes at 37°C.…”

“…This passage also corresponds to the passage of CDCs transplanted into our porcine model of hibernating myocardium [1, 2]. As a control, we also isolated exosomes from normal human dermal fibroblasts (NHDF) at P4.…”

“…While they stimulate regeneration, angiogenesis, and functional improvement in infarcted myocardium [11, 12], these benefits likely occur by indirect mechanisms. This conclusion is based on the fact that most of the newly regenerated myocardium and vasculature are from cells of endogenous origin [2, 13] and the beneficial effects of CDCs persist long after the injected cells have been cleared by the host [14]. Thus, paracrine factors released by CDCs have become candidates for effecting cardiac repair.…”

Effect of the stop-flow technique on cardiac retention of c-kit positive human cardiac stem cells after intracoronary infusion in a porcine model of chronic ischemic cardiomyopathy

“…This would lead to an underestimation of cell numbers. Additionally, PCR-based methods, as well as other methods such as fluorescence in situ hybridization of sex-mismatched donor-recipient pairs [25] and nuclear affinity labeling for cell tracking [13], enable quantification of cell numbers only in small myocardial samples assumed to be representative of the whole heart; these numbers must then be normalized to total myocardial weight to calculate global cardiac retention. Because cells may be distributed heterogeneously within the heart, as observed in the present study (Figs.…”

Cell-based therapies for ischemic cardiomyopathy : investigations of intramyocardial retention and safety of high dose intracoronary delivery of c-kit positive cardiac progenitor cells, and therapeutic utility of a novel population of cardiac mesenchymal stem cells expressing stage-specific embryonic antigen-3 (SSEA-3).

“…188 The same group observed a similar safety and efficacy profile following intracoronary infusion (without stop flow) of 30 million cardiosphere-derived cells divided among each of three coronary vessels. 189 Again, no significant TnI elevation was observed.…”