Expression of Mitochondrial Fusion Proteins is Increased Within Hibernating Myocardium Following CABG

Background: We have shown that expression of mitochondrial electron transport proteins is reduced 4 weeks following bypass surgery (CABG). In this study, we tested whether the expression of mitochondrial fusion proteins (Opa1) and mitofusins (Mfn 1&2), as an indicator of early recovery of the mitochondrial proteome, is increased post-CABG. Methods: Nine pigs underwent placement of a constrictor on the LAD artery and had reduced function at 12 weeks. Four pigs underwent off-pump revascularization with a left internal mammary artery graft beyond the LAD stenosis (+CABG). Patent grafts were confirmed by CTA post-CABG. Five hibernating pigs without CABG served as comparisons (-CABG). Data were compared to 5 SHAM-operated controls (Con) without LAD constrictor. Prior to sacrifice, blood flows by μspheres were determined during dobutamine (40 μg/kg/min). Post-sacrifice, the content of mitochondrial fusion proteins and nuclear-bound PGC1α was determined by westerns. Results: In the +CABG Group, blood flows durin...