Heart function changes following transplantation of autologous bone marrow mononuclear cells in a canine model of heart failure induced by rapid ventricular pacing: Pathological image analysis of collagen fiber / 中国组织工程研究

ABSTRACT

BACKGROUND: Stem cell regeneration can repair injured myocardium. However, bone marrow mononuclear cells (BM-MNCs) transplantation for non-ischemic heart failure remains poorly understood.OBJECTIVE: To investigate effect of transplantation of autologous BM-MNCs on cardiac function in canine model of heart failure by rapid ventricular pacing. METHODS: Implantation and model control groups were subjected to model establishment of heart failure by rapid pacing of apex of right ventricle, and respectively injected with CM-DiI-labeled BM-MNCs and normal saline into myocardium. After 4 weeks, all dogs were sacrificed, and specimens of myocardium were collected from the apex, anterior wall and interventricular septum. All specimens were labeled by FITC. Myocardial fibrosis conditions of implanted cells were observed, collagen volume fraction was determined, and hemodynamic indexes were measured. RESULTS AND CONCLUSION: BM-MNCs labeled by CM-DiI and FITC were observed in the transplantation group showing yellow fluorescence, while in the control group FITC-labeled green fluorescence was seen. HE and Masson staining showed that inflammatory cell infiltration in interstitial matrix, displaying interstitial fibrosis and myocardial fibrosis in model control group, but no obvious inflammatory cell infiltration or myocardial fibrosis was observed in the transplantation group, indicating a success model establishment of heart failure by rapid ventricular pacing. Compared with model control group, the collagen volume fraction decreased significantly (P < 0.05), ejection fracture remarkably increased (P < 0.05), but left ventricular end-diastolic and end-systolic diameter remained unchanged in the transplantation group (P > 0.05). Autologous BM-MNCs in canine model of heart failure show myocardium-like cells differentiation, and improve heart function, which possibly associate with the ability of inhibiting the myocardial fibrosis.