Ultrasound Induced Angiogenesis

Ischemia is the underlying pathology of many diseases which lead to poor circulation, necrosis and eventual loss of function. The progression of vascular occlusive diseases, more specifically, often result in insufficient oxygenation and claudication or critical limb ischemia (Schirmer and Royen 2004). In an effort to combat the effects of these diseases numerous attempts to induce angiogenesis and arteriogenesis, as a means of collateral blood supply, have been made. While cellular/molecular (Messina et al. 2002, Guan et al. 2007) and genetic (Jiang et al. 2007, Hung et al. 2007, Hiasa et al. 2004) endeavors continue to be pursued, these have not translated well into the clinic as apparent by the multitude of literature, but persisting complications. Ultrasound has been reviewed for its therapeutic effects since the early 1960s (Paul et al. 1960, Galitsky et al. 1964) and continues to show promise for angiogenic induction in ischemic tissues both without (Barzelai et al. 2005) and with the use of contrast agents (Song et al. 2002, Song et al. 2004, Chappell et al. 2005). Other literature combines the genetic/cellular methods with ultrasound contrast agents (UCAs) to promote the biological effect (Price et al. 1998, Zen et al. 2006, Korpanty et al. 2007, Leong-Poi et al. 2007).

While there are some central dogmas for exposure conditions to encourage collateral growth (i.e. low frequency, low pressure), the pulsing conditions, use of contrast agents, intensities, and the observed date at which angiogenesis is observed all vary. Because of the discrepancies in the literature, it is difficult to draw conclusions about possible exposure conditions in patients. The already existing phenomena of ultrasound contrast agent induced angiogenesis needs to be validated if this therapeutic application is to transition to the clinic. For patients with vascular occlusive disease, not only do general trends need to be elucidated, but also the mechanism behind the therapy. Therefore, the first objective of this study is to develop an understanding of the angiogenic progression in UCA-treated normal muscle via a survival study. In doing so, the underlying principles of exposure conditions will be used to assess the response at 3, 6, 13, 20, and 27 days. This information will be used for the second objective: to understand how the pulse duration, PRPA, and presence or absence of contrast agents affects the response (at the peak time point for angiogenesis). Finally, the mechanism by which ultrasound and ultrasound contrast agents exert their effect will be explored using the angiogenic marker VEGF, quantitative real time PCR for VEGF mRNA expression, and capillary density as quantifiable end points.

S. Barzelai, O.Sharabani-Yosef, R. Holbova, D.Castel, R. Walsen, S.Engelberg and M. Scheinowitz. Low Intensity Ultrasound Induces Angiogenesis in Rat Hind Limb Ischemia. Ultrasound in Medicine & Biology, 32, 139-145, 2006.

J.Chappell, A. Kilbanov and R. Price. Ultrasound Microbubble Induced Neovascularization in Mouse Skeletal muscle. Ultrasound in Medicine & Biology, 31, 1411-1422, 2005.

A.B. Galitsky and S. I. Levina. Vascular Origin of Trophic Ulcers and Application of Ultrasound as Preoperative Treatment to Plastic Surgery. Acta Chirurgiae Plasticae, 6, 271-278, 1964.

J. Guan, J.J. Stankus and W. R. Wagner. Biodegradable Elastomeric Scaffolds with Basic Fibroblast Growth Factor Release. Journal of Controlled Release, 120, 70-78, 2007.

K. Hiasa, M. Ishibashi, K. Ohtani, S. Inoue, Q. Zhao, S. Kitamoto, M. Sata, T. Ichiki, A. Takeshita and E. Egashira. Gene Transfer of Stromal Cell-derived Factor-1 Alpha Enhances Ischemic Vasculogenesis and Angiogenesis via Vascular Endothelial Growth Factor/Edothelial Nitric Oxide Synthase-Relted Pathway : Next Generation Chemokine Therapy for Therapeutic Neovascularization. Circulation, 109, 2454-2461, 2004.

S. C. Hung, R.R. Pochampally, S.C. Chen, S. C. Hsu and D. J. Prockop. Angiogenic Effects of Human Multipotent Stromal Cells (MSCs). Conditioned Medium Activates the PI3K-Akt Pathway in Hypoxic Endothelial Cells to Inhibit Apoptosis, Increase Survival, and Stimulate Angiogenesis. Stem Cells, 25, 1-17, 2007.

M. Jiang, B. Wang, C. Wang, B. He, H. Fan, T. B. Guo, Q. Shao, L. Gao and Y. Liu. Angiogenesis by Transplantation of HIF-1alpha Modified EPCs into Ischemic Limbs. Journal of Cellular Biochemistry, 103, 321-334, 2008.

G. Korpanty, J. G. Carbon, P.A. Grayburn, J. B. Fleming and R. A. Brekken. Monitoring Response to Anticancer Therapy by Targeting Microbubbles to Tumor Vasculature. Clinical Cancer Research, 13, 323-330, 2007.

H. Leong-Poi, M. A. Kuliszewski, M. Lekas, M. Sibbald, K. Teichert-Kuliszewska, A. L. Klibanov, D. J. Stewart and J. R. Lindner. Therapeutic Arteriogenesis by Ultrasound-Mediated Vegf165 Plasmid Gene Delivery to Chronically Ischemic Skeletal Muscle. Circulation Research, 101, 295-303, 2007.

L. M. Messina, L.S. Brevetti, D. S. Chang, R. Paek and R. Sarkar. Therapeutic Angiogenesis for Critical Limb Ischemia: Invited Commentary. Journal of Controlled Release. 78, 285-294, 2002.

B. J. Paul, C. W. La Fratta, A. R. Dawson, E. Baab and F. Bullock. Use of Ultrasound in the Treatment of Pressure Sores in Patients with Spinal Cord Injury. Archives of Physical Medicine and Rehabilitation, 41, 438-440, 1960.

R. J. Price, D. M. Skyba, S. Kaul and T. C. Skalak. Delivery of Colloidal Particles and Red Blood Cells to Tissue through Microvessel Ruptures Created by Targeted Microbubble Destruction with Ultrasound. Circulation, 198, 1264–67, 1998.

S. H. Schirmer and N. V. Royen. Stimulation of Collateral Artery Growth: A Potential Treatment for Peripheral Artery Disease. Expert Review of Cardiovascular Therapy, 2, 581–588, 2004.

J. Song, J. C. Chappell, M. Qi, E. J. VanBieson, S. Kaul and R. J. Price. Influence of Injection Site, Microvascular Pressure, and Ultrasound Variables on Microbubble-mediated Delivery of Microspheres to Muscle. Journal of the American College of Cardiology, 39, 726-731, 2002.

J.Song, P. S. Cottler, A. L. Klibanov, S. Kaul and R. J. Price.Microvascular Remodeling and Accelerated Hyperemia Blood Flow Restoration in Arterially Occluded Skeletal Muscle Exposed to Ultrasonic Microbubble Destruction. American Journal of Physiology. Heart and Circulatory Physiology, 287, H2754–H2761, 2004.

K. Zen, M. Okigaki, Y. Hosokawa, Y. Adachi, Y. Nozawa, M. Takamiya, T. Tatsumi, N. Urao, K. Tateishi, T. Takahashi and H.Matsubara. Myocardium-targeted Delivery of Endothelial Progenitor Cells by Ultrasound-mediated Microbubble Destruction Improves Cardiac Function via an Angiogenic Response. Journal of Molecular and Cellular Cardiology, 40, 799-809, 2006.