Serum soluble Fas (sFas) can block the binding between Fas-ligand and Fas-receptor on cell membrane, and is an inhibitor of apoptosis. SFas gene therapy using adenovirus vector injected into the hindlimb muscles was performed for cardiac failure of UM-X 7.1 hamster, a model of dilated cardiomyopathy.
1. In this model, serum sfas level 4 weeks after gene therapy was markedly increased in the sFas gene therapy group, compared to the control group with Lac Z gene (500mg/ml vs 0 of control).
2. However, survival rate 5 and 10 weeks later was similar between the sFas gene therapy group (71% and 50%) and the Lac Z control group (72% and 48%).
3. There was no significant difference of LV endodiastolic dimension, ejection fraction, and endodiastolic pressure 10 weeks after gene therapy. Also, heart weight, the extent of fibrosis, the % of TUNEL-positive cardiomyocytes, and the transverse size of cardiomyocytes did not show significant differences between the two groups.
In conclusion, sFas gene therapy does not inhibit the progression of cardiac failure in UM-X 7.1 hamster, in spite of marked increase of serum sFas. This suggests that Fas-Fas ligand system is independent of the progression of dilated cardiomyopathy of UM-X 7.1 hamster.