Transplantation of cardiotrophin-1–expressing myoblasts to the left ventricular wall alleviates the transition from compensatory hypertrophy to congestive heart failure in Dahl salt-sensitive hypertensive rats

Abstract

ObjectivesWe investigated whether autologous transplantation of skeletal myoblasts (MB) transferred with cardiotrophin-1 (CT-1) gene could retard the transition to heart failure (HF) in Dahl salt-sensitive (DS) hypertensive rats. BackgroundAlthough MB is a therapeutic candidate for chronic HF, little is known about the efficiency of this strategy when applied in nonischemic HF. Cardiotrophin-1 has potent hypertrophic and survival effects on cardiac myocytes. We hypothesized that transplantation of CT-1–expressing myoblasts could provide cardioprotective effects against ventricular remodeling in DS hypertensive rats. MethodsThe DS rats were fed a high salt diet for 6 weeks and developed left ventricular (LV) hypertrophy at 11 weeks. At this stage, animals underwent MB to the myocardium with skeletal myoblasts transferred with CT-1 gene using retrovirus (transplantation of CT-1–expressing myoblasts [MB + CT], n = 31) or myoblasts alone (MB, n = 31). The sham group rats were injected with phosphate-buffered saline (n = 24). ResultsAt 17 weeks, MB and MB + CT groups showed a significant alleviation of LV dilation and contractile dysfunction compared with the sham group. The degree of alleviation was significantly greater in the MB + CT group than the MB group (LV end-diastolic dimension: sham 7.06 ± 0.14 mm, MB 6.51 ± 0.16 mm, MB + CT 6.24 ± 0.07 mm; fractional shortening: sham 32.1 ± 1.4%, MB 38.5 ± 1.5%, MB + CT 43.2 ± 0.8%). Histological examination revealed that the myocyte size was 20% larger in the MB + CT group at 17 weeks than in the age-matched sham group. Upregulation of renin-angiotensin and endothelin systems during the transition to HF was attenuated by myoblast transplantation, and this effect was enhanced in the MB + CT group. ConclusionsTransplantation of skeletal myoblasts combined with CT-1-gene transfer could be a useful therapeutic strategy for HF.