Intracoronary allogeneic cardiosphere-derived stem cells are safe for use in dogs with dilated cardiomyopathy

Abstract

Cardiosphere-derived cells (CDCs) have been shown to reduce scar size and increase viable myocardium in human patients with mild/moderate myocardial infarction. Studies in rodent models suggest that CDC therapy may confer therapeutic benefits in patients with non-ischaemic dilated cardiomyopathy (DCM). We sought to determine the safety and efficacy of allogeneic CDC in a large animal (canine) model of spontaneous DCM. Canine CDCs (cCDCs) were grown from a donor dog heart. Similar to human CDCs, cCDCs express CD105 and are slightly positive for c-kit and CD90. Thirty million of allogeneic cCDCs was infused into the coronary vessels of Doberman pinscher dogs with spontaneous DCM. Adverse events were closely monitored, and cardiac functions were measured by echocardiography. No adverse events occurred during and after cell infusion. Histology on dog hearts (after natural death) revealed no sign of immune rejection from the transplanted cells.

Keywords: allogeneic; cardiosphere-derived cells; dilated cardiomyopathy; dogs; stem cell therapy.

Figure 1

Derivation and culture of canine CDCs. (A) Schematic diagram showing the derivation of canine CDC a of Beagle dog. (B) Outgrowth cells from plated myocardial tissues. (C) Cardiosphere formation in suspension culture. (D) CDCs dissociated from cardiospheres. (E) Expressions of CD105, CD90, ckit by flow cytometry in canine CDCs. Scale bars = 50 μm in all images.

Figure 2

Cell infusion procedure. (A) Viability of CDCs stored at 4°C. (B) Intracoronary cell infusion design. (C) Coronary angiography showing catheter placement in left main and RCA. (D) Schematic diagram showing the infusion dose.

Figure 3

Effects of CDC therapy on cardiac function. (A) Representative echocardiography images showing control and CDC‐treated dogs at end‐point. (B) Fractional shortening (FS%) comparison between control and CDC groups. (C) Treatment effects as gauged by change in FS%. (D) WT% comparison between control and CDC groups. (E) Treatment effects as gauged by change in WT%. End‐point was consistent for all dogs and taken at the 3‐month time‐point.

Figure 4

Intragroup analysis of FS% and WT% in control and CDC‐treated animals. (A) FS% at baseline and end‐point for the dogs in the control group. (B) WT% at baseline and end‐point for the dogs in the control group. (C) FS% at baseline and end‐point for the dogs in the CDC group. (B) WT% at baseline and end‐point for the dogs in the CDC group. End‐point was consistent for all dogs and taken at the 3‐month time‐point.

Figure 5

Left ventricle dimensions. (A) Comparison of LVDd change over the time between control and CDC groups. (B) LVDd at baseline and end‐point for the dogs in the control group (C) LVDd at baseline and end‐point for the dogs in the CDC group. (D) Comparison of LVDs change over the time between control and CDC groups. (E) LVDs at baseline and end‐point for the dogs in the control group. (F) LVDs at baseline and end‐point for the dogs in the control group. End‐point was consistent for all dogs and taken at the 3‐month time‐point.

Figure 6

Cardiac failure and injury markers. (A) Comparison of serum BNP levels in control and CDC groups before and after infusion. (B) Comparison of serum cTNI levels in control and CDC groups before and after infusion. End‐point was consistent for all dogs and taken at the 3‐month time‐point.

Figure 7

Heart histology. (A) Transversal section of CDC‐treated canine heart (B) Survival data comparing control (n = 3) and CDC‐treated (n = 5) groups. (C) Representative FISH stain showing lack of engraftment of infused male allogeneic cCDC in native female Doberman heart. (D) Haematoxylin and eosin staining showing no infiltration of cell nuclei from immune response, indicating allogeneic CDC infusion did not stimulate rejection. (E) A representative section from control animal heart. (F) A representative section from healthy Doberman heart. Scale bars = 5 and 100 μm