Restoration of coronary collateral growth in the Zucker obese rat: impact of VEGF and ecSOD.

The metabolic syndrome (MS), a condition characterized by several risk factors for coronary artery disease, including obesity, is associated with endothelial dysfunction and oxidative stress. Because proper endothelial function is essential for signaling of certain growth factors (vascular endothelial growth factor, VEGF) we hypothesized that coronary collateral growth (CCG) is impaired in a model of the MS. To test this hypothesis, we stimulated coronary collateral growth in pre-diabetic Zucker obese fatty rats (OZR) and lean littermates (LZR) by using episodic, repetitive ischemia (RI: 40 s left anterior descending arterial occlusion, 24/d for 14 d).

Application of mesenchymal stem cell-derived cardiomyocytes as bio-pacemakers: current status and problems to be solved.

Bone marrow mesenchymal stem cells (CMG cells) are multipotent and can be induced by 5-azacytidine to differentiate into cardiomyocytes. We characterized the electrophysiological properties of these cardiomyocytes and investigated their potential for use as transplantable bio-pacemakers. After differentiation, action potentials in spontaneously beating cardiomyocytes were initially sinus node-like, but subsequently became ventricular cardiomyocyte-like.

Purified cardiomyocytes from bone marrow mesenchymal stem cells produce stable intracardiac grafts in mice.

Objective: We have previously isolated cardiomyogenic cells from murine bone marrow (CMG cells). Regenerated cardiomyocytes are important candidates for cell transplantation, but as they are stem cell derived, they can be contaminated with various cell types, thereby requiring characterization and purification. Our objectives were to increase the efficiency of cell transplantation and to protect the recipients from possible adverse effects using an efficient and effective purification process as well as to characterize regenerated cardiomyocytes.

Autologous vascular smooth muscle cell-based myocardial gene therapy to induce coronary collateral growth.

For therapeutic angiogenesis to achieve clinical relevance, it must be effective, with minimal side effects to other end organ systems. We developed a cardiac-specific gene delivery mechanism by transfecting autologous vascular smooth muscle cells (VSMC) with VEGF and administering these cells via intracoronary injection. We evaluated the efficacy of this protocol by its ability to stimulate angiogenesis in the presence of a subthreshold stimulus for collateralization.

Angiostatin and matrix metalloprotease expression following ischemic acute renal failure.

Ischemic injury to the kidney results in blood vessel loss and predisposition to chronic renal disease. Angiostatin is a proteolytic cleavage product of plasminogen that inhibits angiogenesis, promotes apoptosis of endothelial cells, and disrupts capillary integrity. A combination of lysine-Sepharose enrichment followed by Western blotting was used to study the expression of angiostatin in response to the induction of ischemic renal injury.

Inhomogeneous vasodilatory responses of rat tail arteries to heat stress: evaluation by synchrotron radiation microangiography.

Tail blood flow is crucial for dissipating body heat in rats. Angiographies are convenient tools to evaluate tail circulation. However, conventional angiographies do not have sufficient sensitivity or spatial resolution for small vessels.