Proteomic Mechanism of Myocardial Angiogenesis Augmented by Remote Ischemic Training of Skeletal Muscle in Rabbit

Methods: The rabbits were grouped by RIT, myocardial ischemia without RIT (MI), and sham-operation (Sham). Controlled myocardial ischemia was modeled by a balloon constrictor implanted on their left ventricular branch (LVB) in a New Zealand rabbit. RIT was induced by four cycles of 10-minute ischemia followed by 10 minutes of reperfusion using tourniquets on the hind limbs of the myocardial ischemia models for 4 weeks. The myocardial samples were subjected to two dimensional electrophoresis and MALDI TOF for protein identification. The angiogenesis was documented by using microspheres to measure the relative regional blood flow, immunohistochemistry to assess capillary density (Factor VIII), and Western blotting to measure the vascular endothelial growth factor (VEGF) levels. Results: Thirty-eight differentially expressed protein spots between RIT and MI were separated by two-dimensional gel electrophoresis, and of those, 22 proteins were identified by mass spectrometry. The regional blood flow, capillary density and VEGF in RIT were 35%, 49% and 28% higher than MI (p < 0.01). The increase of regional blood flow and capillary density were highly correlated with VEGF (r = 0.74 and r = 0.67, respectively; p < 0.01). Both RIT and MI groups exhibited stronger angiogenesis than sham treatment (p < 0.01). Conclusions: Augmentation of angiogenesis in ischemic myocardium by RIT has identical identified proteomic findings with differentially expressed proteins.