title: Ultrasound-targeted antisense oligonucleotide attenuates ischemia/reperfusion-induced myocardial tumor necrosis factor-alpha.
abstract: Ultrasound contrast agents are now emerging as effective vehicles for delivering therapeutic agents to target tissues. In the present study, we used ultrasound-targeted, contrast-bound antisense oligonucleotides to inhibit the expression of tumor necrosis factor-alpha (TNF-alpha), a proinflammatory cytokine with negative inotropic effects. We compared the efficacy of left ventricular vs. intravenous administration and determined the optimal time for delivery. WKY rats were treated with perfluorocarbon-exposed sonicated dextrose albumin (PESDA) microspheres incubated with 100 microg of antisense oligonucleotide directed against TNF-alpha. Contrast was infused into either the superior vena cava or the left ventricular cavity along with simultaneous application of ultrasound. Twenty-four hours later, the animals underwent 15 min of ischemia and 2 h reperfusion. Control animals underwent sham operation only, ischemia/reperfusion only, or received PESDA only. A second group received treatment just prior to, or immediately after the onset of ischemia. At the end of the experimental period, hearts were removed and analyzed for TNF-alpha by northern and western blotting. While no TNF-alpha expression was detected in sham-operated animals, robust expression of TNF-alpha mRNA and protein was seen in controls treated with ultrasound and PESDA alone. In contrast, intravenous or left ventricular administration of antisense oligonucleotides significantly inhibited ischemia/reperfusion-induced TNF-alpha expression. Direct delivery into the left ventricular cavity was more effective than intravenous administration, and delivery just prior to ischemia was most effective in attenuating TNF-alpha expression. Furthermore, attenuation of TNF-alpha expression also significantly inhibited other post-ischemic inflammatory mediators including IL-1beta and intercellular adhesion molecule-1 (ICAM-1). Thus, ultrasound-targeted antisense oligonucleotides can effectively attenuate post-ischemic cytokine expression when delivered in a clinically relevant time frame, obviating the need for pretreatment.
authors.affiliation: Department of Medicine, Division of Cardiology, M/C 7872, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA. erikson@uthscsa.edu
authors.forename: John M
authors.initials: JM
authors.lastname: Erikson
authors.forename: Gregory L
authors.initials: GL
authors.lastname: Freeman
authors.forename: Bysani
authors.initials: B
authors.lastname: Chandrasekar
mesh_terms: D009206:Myocardium / Q000378:metabolism*; D016376:Oligonucleotides, Antisense / Q000008:administration & dosage / Q000378:metabolism*; D015427:Reperfusion Injury / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*; D014465:Ultrasonics
chemical_list: D016376:Oligonucleotides, Antisense; D014409:Tumor Necrosis Factor-alpha