Abstract P021: Adipose-Derived Stromal Cell Therapy Stabilizes Cardiac Function and Improves Border Zone Remodeling After Coronary Occlusion in Rats
Recent studies have identified adipose tissue as a new source of mesenchymal stem cells for therapy. The purpose of this study was to investigate the therapy with rat adipose derived stromal cells (ASC) in a rat model of healed myocardial infarction (MI). ASC from inguinal subcutaneous adipose tissue of male Wistar rats were isolated by enzymatic digestion and filtration. Cells were then cultured until passage 3. Four weeks after ligation of the left coronary artery of female rats, a suspension of either 100µl with PBS + Matrigel + 2 x 106 ASC labeled with Hoechst (n=11) or 100µ;l of PBS + Matrigel (n=10) was injected along the borders of the ventricular wall scar tissue. A sham operated group (n=5) was submitted to the same surgical procedure except permanent ligation of left coronary artery. Cardiac performance was assessed by electro and echocardiogram. Echo was performed prior to injections (baseline-BL) and six weeks after injections (follow-up - FU), and values after treatment were normalized by values obtained before treatment. Hemodynamic measurements were performed 6 weeks after injections. All data are expressed as mean ± SEM. Student's paired or unpaired T test was used to compare the same group in two different times or two distinct groups, while two way ANOVA was used to compare more than two groups along different times and p was set at <0.05. All infarcted animals exhibited cardiac function impairment. Ejection fraction (EF), shortening fractional area (SFA) and left ventricular akynesia (LVA) were similar between infarcted groups before treatment. Six weeks after therapy, ASC group showed significant improvement in all three Echo indexes in comparison to vehicle group. In non-anesthetized animals dp/dt+ was also significantly higher in ASC when compared to vehicle. In agreement with functional improvement scar area was diminished in the ASC group. We conclude that ASC stabilize cardiac function in infarcted rats when administered directly to the myocardium.