Cardiac-targeted RNA interference mediated by an AAV9 vector improves cardiac function in coxsackievirus B3 cardiomyopathy

• Published in: Journal of molecular medicine (Berlin, Germany) Germany), 2008-09, Vol.86 (9), p.987-997
• Main Authors: Fechner, Henry, Sipo, Isaac, Westermann, Dirk, Pinkert, Sandra, Wang, Xiaomin, Suckau, Lennart, Kurreck, Jens, Zeichhardt, Heinz, Müller, Oliver, Vetter, Roland, Erdmann, Volker, Tschope, Carsten, Poller, Wolfgang
• Format: Article
• Language: English
• Subjects: Adeno-associated virus; Adult; Animals; Base Sequence; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Cardiology. Vascular system; Cardiomyopathies - genetics; Cardiomyopathies - therapy; Cardiomyopathies - virology; Cell Line; Child; Coxsackievirus B3; Coxsackievirus Infections - therapy; Dependovirus - genetics; Dependovirus - metabolism; Enterovirus B, Human - enzymology; Enterovirus B, Human - genetics; General aspects; Genetic Vectors; Heart; Heart - physiology; Hemodynamics; Human Genetics; Humans; Internal Medicine; Medical sciences; Mice; Molecular Medicine; Molecular Sequence Data; Myocarditis. Cardiomyopathies; Myocardium - cytology; Myocardium - metabolism; Original Paper; Rats; RNA Interference; RNA Replicase - genetics; RNA Replicase - metabolism; RNA, Viral; Viral Proteins - genetics; Viral Proteins - metabolism
• ISSN: 0946-2716; 1432-1440
• DOI: 10.1007/s00109-008-0363-x

RNA interference (RNAi) has potential to be a novel therapeutic strategy in diverse areas of medicine. In this paper, we report on targeted RNAi for the treatment of a viral cardiomyopathy, which is a major cause of sudden cardiac death or terminal heart failure in children and young adults. RNAi therapy employs small regulatory RNAs to achieve its effect, but in vivo use of synthetic small interfering RNAs is limited by instability in plasma and low transfer into target cells. We instead evaluated an RNAi strategy using short hairpin RNA (shRdRp) directed at the RNA polymerase (RdRP) of coxsackievirus B3 (CoxB3) in HeLa cells, primary rat cardiomyocytes (PNCMs) and CoxB3-infected mice in vivo. A conventional AAV2 vector expressing shRdRp protected HeLa against virus-induced death, but this vector type was unable to transduce PNCMs. In contrast, an analogous pseudotyped AAV2.6 vector was protective also in PNCMs and reduced virus replication by >3 log 10 steps. Finally, we evaluated the intravenous treatment of mice with an AAV2.9-shRdRp vector because AAV9 carries the most cardiotropic AAV capsid currently known for in vivo use. Mice with CoxB3 cardiomyopathy had disturbed left ventricular (LV) function with impaired parameters of contractility (d P /d t max  = 3,006 ± 287 vs. 7,482 ± 487 mmHg/s, p